Aaron is a name of subtle contrasts: an unusual spelling that is easily recognizable; a solid Biblical choice that doesn’t feel exclusively tied to religion; a well-established name for boys but sometimes confused with the girls’ name, Erin; used internationally but with notably different pronunciations; classic like Andrew but not out of place with recent favorites like Weston or Jayden. 
All things considered, Aaron’s enduring popularity feels at once surprising and obvious. And endure it does. For the last 50 years, it has been a staple in the US Top 100, and it remains a solid favorite in a number of European countries, from France to Switzerland. 
The origins of the name are debated, with some saying from Ancient Egypt, and has the meaning “warrior lion”, while others believe it is derived from Hebrew, with meanings such as “high mountain” or “exalted”. 
In the Old Testament, Aaron is a powerful figure, acting as a spokesman for his brother, Moses. He produced miracles and plagues to intimidate the pharaoh for enslaving the Israelites, and he was appointed by God as the first high priest. 
Other notable namesakes include the American politician, Aaron Burr, the composer, Aaron Copeland, and actors Aaron Ekhart, Aaron Taylor-Johnson, and Aaron Paul. The name has literary credentials too, with Shakespeare, John Steinbeck, and George Eliot using it in their works. 
Given to more than 4500 babies in the US every year, the soft sound of Aaron’s double vowels continues to hold an appealing gentleness for parents today. 
But why does Aaron have that unusual beginning and why is it pronounced differently across the world? 
Well, the original Hebrew name is Aharon, pronounced with 3 syllables, however, this sound had no equivalent in Greek. When Jewish scriptures were translated then, it was recorded as “Aaron”. While the Romans and Greeks might still have said “a-ha-ron”, it was later Anglicized in the 17th century to “air-un”. 
In England however, it is often said as “a-run”, where “a” is like the first sound of “apple”. This is likely down to people confusing it with the English name “Aron”, or because they were influenced by the Scottish Isle of Arran and the Irish Aran Islands. 
More broadly, pronunciation varies when Aaron is translated into the many languages used around the world. In German, it is A-rawn, while in Finnish, it is AH-rone or Aaro. In Arabic, Urdu and Turkish, it becomes Harun or Haroon and across Africa, it might be Haruna or Haron. 
Love Aaron but slightly put off by its widespread popularity? You could try Alden, Ansel, Taran, Canaan, Ariel or Abram.

Aaron

Caleb is an attractive Old Testament name that has been in the US Top 100 for nearly three decades now. Consistently popular but never too popular, Caleb feels more like a classic than a momentary trend.
 Caleb has two potential derivations, the first being from the Hebrew kelev, meaning "dog," and the second from the Hebrew components kal and lev, together meaning "whole heart." 
 
In the Old Testament Caleb is one of only two ancient Israelites (Joshua was the other) who set out from Egypt to finally enter the promised land. 
 
Caleb Garth is a character in George Eliot's Middlemarch. Caleb was the full name of James Dean's character Cal in East of Eden, and the name has also been heard on Desperate Housewives and Buffy the Vampire Slayer.Julianne Moore chose Caleb for her son, as did Bo Bice. The shortform Cale is also rising in popularity, and the current Kaleb spelling picks up on the K-to-C initial trend.

Caleb

Carrie lives on mainly on the screen, as the new/old antiheroine of Stephen King's classic Carrie, as turn-of-the-21st-century diva Carrie Bradshaw of Sex & The City, and as Claire Danes' Emmy-winning character Carrie Mathison of Homeland. In real life, however, Carrie dropped off the Top 1000 a handful of years ago and, while the name retains some charm, shows no signs of making an imminent comeback. Try Cara instead.

Carrie

This alternative spelling of Chastity peaked all the way up at #253 in 1976, and hung on in the US Top 1000 until 2008. Both have now fallen out of favor.

Chasity

Chelsea was last fashionable around the time First Daughter Chelsea Clinton was born, ranking in the Top 25 in the early 1990s.

Chelsey never hit the heights of the original. About 40 baby girls were named Chelsey in the US last year, and about ten times that many called Chelsea.

Chelsey

Christopher derived from the Greek Christophoros, which is composed of the elements Christos, referring to Christ, and phero, meaning "to bear." 
 
The name was originally used figuratively, to represent the bearing of Christ in one’s heart. Later it became used to honor Saint Christopher, a third century martyr who became the protective saint of travelers, reflecting the legend of Christopher being the giant who carried the Christ Child over a river.
 
Christopher is an evergreen classic that dropped from Top 25 status in 2013, in spite of its appealingly strong, sincere, straightforward image, combined with a softer, more modern sound than, say, Robert or Richard.
 
The name appeals to a wide range of parents, and has been chosen by several celebrities, including Sean "Diddy" Combs.
 
The almost ubiquitous American nickname is Chris, but a more recent one is Topher, and there are British variations that might add a more individual spin to the name—Kit, Kip and Christy. Two Christophers known to every schoolchild: Christopher Columbus and Christopher Robin.

Christopher

Cole -- a short name that embodies a lot of richness and depth -- has long been associated with the great songwriter Cole Porter. It's quite popular in Scotland.
 Old King Cole -- which refers to a real British king -- is familiar to all kids. Cole was the name of the child in The Sixth Sense and was also the name of -- sorry -- the notorious outlaw Cole Younger, who was born Thomas Coleman.

Cole

The Top 10 boys' name Elijah is derived from the Hebrew name Eliyahu, composed of the elements ’el and yah, both of which refer to God. In the Old Testament, Elijah was the prophet who went to heaven in a chariot of fire, a story sure to inspire any young Elijah.
 Like many biblical patriarch names, Elijah was on a long downward slide from the 19th century until the late 1960s, when it reversed course and headed uphill. Elijah was rejuvenated when Cher and Greg Allman bestowed it on their son Elijah Blue in 1976, and got another shot of youth serum via young actor Elijah Wood.
 Among other celebrities who have chosen Elijah for their boys are Donnie Wahlberg, James Spader, Tracy Nelson, Wynonna Judd and Bono (who followed it with <a href="https://nameberry.com/list/673/middle-names">middle names</a> Bob Patricus Guggi G.).
 Elijah figures in the Jewish, Christian and Muslim religions. There are numerous songs containing the name, and Elijah is also a character in many films and books—including Charles Dickens's Martin Chuzzlewit.
 Elias is the related, Greek variation of Elijah, also quite popular. Eli is a separate, unrelated name, though sometimes used as a short form of both Elijah and Elias.

Elijah

Elizabeth is one of the most popular girls' names of all time, the female equivalent of James or William. Yet Elizabeth has so much going for it—rich history, broad appeal, and timeless style—that no matter how many little girls are named Lizzie, Eliza, and Beth, you can still make Elizabeth your own. 
 
Elizabeth is derived from the Hebrew name Elisheva, formed by the components ’el, meaning "God," and shava’, "oath." In the Bible, Elizabeth was the mother of John the Baptist, and two of England's most notable queens have been Elizabeth I and II. Another memorable bearer was Elizabeth Taylor—who hated to be called Liz.
 
Elizabeth nicknames on the table today include Libby, Bess, Tibby, and even the so-antiquated-it's-cool Betty. Also in play is the fashionable Eliza along with Lilibet, Queen Elizabeth's childhood nickname more recently used by Prince Harry and wife Meghan for their daughter, Lilibet Diana. 
 
Author and publishing magnate Zibby Owens introduced her zippy Elizabeth nickname to the ever-lengthening list of variations.
 
There has been only one year since 1880 that Elizabeth slipped one place below the Top 25, and that was in 1945—when Betty was Number 11. Today, it holds fast as one of the most classic and usable <a href="https://nameberry.com/search/girls-names/e">girl names starting with E</a>.
 The Elisabeth spelling, found in several cultures, is represented by such notables as Elisabeth Kubler-Ross, Elisabeth Shue, Elisabeth Moss, and Elisabeth Hasselbeck. 
Elisabeth is nicknamed Bethsy in Buddenbrooks, Bep in The Diary of Anne Frank, and Betsy in Wolverine.

Elizabeth

Grace, a simple and pure virtue name which originally referred to divine grace, is a fashionable classic. In the early 2000s, it seemed headed for the Top 10 but pulled back from the upward trajectory, which you may consider a very good thing.

Grace is one of the most luminous of names, recalling the cool elegance of Grace Kelly, Princess of Monaco. Embraced by Americans of the Victorian era, it was the eleventh most popular name in this country in 1875 and has always ranked among the Top 1000 girl names.

Currently, Grace is the Number 1 girls’ name in Ireland, and ranks highly in other English-speaking countries. In the US, it’s one of the most popular one-syllable middle names for girls.
 
Grace is derived from gratia, the Latin word for "grace." It existed as Gracia in the Middle Ages but was not in common use until the Puritans adopted it along with other Christian attribute names in the sixteenth century. It was used as a <a href="https://nameberry.com/list/373/virtue-names">virtue name</a>, in reference to divine grace — the love and kindness of God.
 
If Grace is too overused for you, consider an international variation like Engracia or Graziella. Some parents have even migrated into the gender neutral camp in search of Grace equivalents such as Gray or Grayson or even Gracelyn. Choosing the nickname Gracie for the birth certificate is a popular option.

Grace

Henry is back. The classic Henry climbed back onto the Top 10 in the US in 2021 for the first time in over a century, and now stands at Number 8.
 Like James and Theodore, Henry is a traditional name that also manages to feel stylish. Despite its popularity, it's not for everyone, but in some upscale American suburbs, it can seem as if every other little boy is named Henry or Theo or Jack.
 Henry was derived from the French Henri, which ultimately comes from the Germanic name Heimrich, made up of the components heim, meaning "home" or "estate," and rich, meaning "ruler." The most famous bearer is Henry VIII of England, best known for having six wives—two of whom he beheaded for not bearing him sons. It’s been used in the British royal family many times since, including for the current prince better known as Harry.
 
Other illustrious Henrys that might provide baby name inspiration include Henry David Thoreau, Henry (Hank) Aaron, Henry James, Henry Ford and Henry Miller.
 Numerous celebs have chosen Henry for their sons, from Julia Roberts to Minnie Driver to Heidi Klum to Colin Farrell.
 Appealing international versions include Arrigo, Enrico, Enzio and Enrique.

Henry

Can a name as virtuous as Hope be cool and trendy? Strangely enough -- yes. But though this optimistic Puritan favorite is experiencing substantial popularity, Hope is too pure and elegant to be corrupted, a lovely classic that deserves all the attention it's getting. 
 Hope, along with Faith and Charity, is one of the three theological virtues, first used as a Christian name in the seventeenth century by the Puritans. Hope and Faith have often been given to twins.
 There have been characters named Hope on four different soap operas. The TV show Raising Hope was about, yes, raising a child named Hope--formerly named Princess Beyonce. Brad Garrett has a daughter named Hope.

Hope

Isabella has been a Top 10 name for girls in the US for two decades now. The Latinate form of Isabel, a variation of Elizabeth which originally derived from the Hebrew name Elisheba, Isabella reigned as Number 1 in 2009 and 2010.
Isabella, which feels both modern and traditional, has incredible cross-cultural appeal to parents from a range of religious and ethnic backgrounds. It's feminine but also substantial, with a long history as a royal and classic name comfortable on the international stage. 
 
Isabella is of course wildly popular in both the English and Spanish speaking worlds, but it also ranks among the Top 100 girls' names in a wide range of western countries, including Germany, the Netherlands, and Scandinavia.
 
Isabella's success is due at least in part to the 'Twilight' effect and lead character Isabella 'Bella' Swan. Some parents choose it to get to the short form Bella, while others prefer to use the irreverent Izzy or Issy, while still others insist on using it in its full four-syllable glory.
 
Variations Isabelle and Isabel are also popular, with the Scottish spelling Isobel another possibility. Newer alternatives include Sabella and Isabetta.
 Isabella is familiar through various European queens, including the Queen of Spain who funded Christopher Columbus, and was used by Shakespeare in Measure for Measure.

Isabella

James is one of the classic Anglo-Saxon names, a stalwart through the ages that is more popular—and yes, stylish—than ever today. It recently came out Number 1 in a poll of America's favorite boys' baby names, and is the most common male name, counting people of all ages, in the US.
 James, which reentered the Top 5 in 2016, is a current favorite among fashionable parents looking for a baby name that has both style and substance. Like Henry and Theodore, it manages to combine these two stellar qualities.
 
An English derivation of the Hebrew name Jacob, James is biblical (the name of two apostles in the New Testament), royal (kings of both England and Scotland), and presidential (with more U.S. Chief Executives -- six -- than any other name). The name James is also shared by countless great writers and entertainers.
 
There are fewer Jimmys, Jimbos or even Jamies these days; the most fashionable form of the name is James itself. Several stylish celebrities have chosen it in recent years for their sons, including Sarah Jessica Parker and Matthew Broderick, Liz Phair, Colin Farrell and Isaac Hanson. Brendan Fehr thought out of the box and named his daughter James, which has now become a fashionable middle names for baby girls..
 James has some interesting foreign variations: Diego and Jaime (Spanish), Jacques (French), Giacomo (Italian), Hamish (Scottish), Jaako (Finnish), Seamus (Irish), Jaap (Dutch) and Jago (Cornish).
 Along with being one of the most popular first names in the US, James is also one of the <a href="https://nameberry.com/blog/top-last-names-in-the-us">most common American last names </a>.

James

John reigned as the most popular of all boys' Christian names for 400 years, from the time the first Crusaders carried it back to Britain until the 1950s. Then American baby namers finally seemed to tire of this straight-arrow, almost anonymous John Doe of names, replacing it with fancier forms like Jonathan and the imported Sean and Ian.
 
John is an English derivative of the Hebrew name Yochanan via the Latin name Iohannes, itself coming from the Greek Ioannes. John was a key name in early Christianity, borne by John the Baptist, John the Apostle and John the Evangelist, plus 84 saints and 23 popes, as well as kings and countless other illustrious notables. Contrary to popular belief, the names John and Jonathan are unrelated, the latter being an elaboration of Nathan.
 
Because many of today's baby Johns get their names for familial rather than stylistic reasons, John isn't as ubiquitous as it once was. For modern parents, the nickname Jack or an international form like Gianni feels much fresher. But John is still one of the Top 10 <a href="https://nameberry.com/search/boys-names/j">boy names starting with J</a> of all time.
 
The international versions of John are perennial classics in their own cultures: the French Jean, the Irish Sean, the Scottish Ian, the Welsh Evan and Ewan, the Italian Giovanni, and Gianni the Spanish Juan, the German Johann/Johannes, the Slavic Jan, the Russian Ivan, and on and on.
 
Celebrities who have gone with the timeless John include Michelle Pfeiffer, Bono, Johnny Depp, Lauryn Hill, Bridget Moynahan, and Rob Lowe.
 
Jon may be an abbreviated spelling of John or a short form of Jonathan.

John

Joseph is one of the most classic names in American nomenclature, popular with parents from many ethnic backgrounds and having dual-religious appeal.

The warm and friendly nickname Joe is the all-time regular guy name, as in Joe Blow, G.I. Joe, etc., celebrated in songs like 'Happiness is Just a Thing Called Joe.' Joe is frequently used on its own, as Kate Winslet did for her son.

Joseph evolved from the Hebrew name Yosef, which was derived from the verb yasaf, meaning "to increase." In the Old Testament, Joseph is the 11th and favorite son of Jacob and Rachel; in the New Testament, it is the name of the carpenter husband of the Virgin Mary, mother of Christ. 
 
Along with Joe, Joey is a usual short form. Variations of Joseph are popular worldwide, including Jose, Giuseppe and Josef, The most popular feminine form of Joseph is Josephine, but Joanna and Joanne are also found today for girls, along with Josie and Jo.

Joseph

Joshua, a Top 10 name from 1983 until 2010, has dropped out of the Top 50 but manages to present a relaxed, attractive image, with a bit of the Old West mixed in with its biblical persona.
 
Joshua was derived from the Hebrew name Yehoshu’a, from the roots yeho, referring to God, and yasha’, meaning "to save." Joshua shares origins with the name Jesus, which comes from the Aramaic variation Yeshu’a.
 An important figure in the Old Testament, Joshua was the successor to Moses who finally led the Israelites into the Promised Land, inspiring the hymn "Joshua Fit the Battle of Jericho."
 
Joshua's soft-sounding middle and vowel ending make it one of the new gentle boys' names, joining Biblical brothers Noah and Asher. The current generation's baby name successors to Joshua include Josiah and Jasper.

Joshua

Mary is the English form of Maria, which ultimately was derived from the Hebrew name Maryam/Mariam. The original meaning of Maryam is uncertain, but theories include "drop of the sea" (from Hebrew roots mar "drop" and yam "sea"); "bitter" (from Hebrew marah "bitterness"); and "beloved" (from the Egyptian root mr).

 Mary, the quintessential New Testament name, was #1 for girls until the mid-twentieth century. Though still popular, Mary is used now mostly for religious or family reasons. If it's style you're after, Mary's many diminutives and derivatives such as Maire, Mamie, May, Mitzi, Molly, Maura, Marietta, and even Maria may seem more fashionable. 

 Mary was the most popular and enduring female Christian name in the English-speaking world (as were Maria and Marie in Spanish and French) until the 1940s. That was when in the US Mary was finally dethroned by such trendy upstarts as Linda and Karen.

 There are six Marys in the Bible, including the Virgin Mary, Mary Magdalene, Mary the sister of Martha and Lazarus, Mary the mother of James and Joseph, and Mary the mother of Mark, and there have been British royal Marys beginning in the sixteenth century. In earlier times Mary was considered too sacred to be used; it finally gained usage in England in the twelfth century, and by the sixteenth had blanketed the female population, to the point where dozens of pet forms had to be contrived to distinguish one Mary in the family from the others.

 The poet Byron deemed Mary a "magic" name, and Bing Crosby proclaimed it "a grand old name." Mary has always been a good-girl name, as reflected by such mid-century icons of propriety and wholesomeness as Mary Poppins and Mary Tyler Moore. The lovely Lady Mary Crawley of Downton Abbey has restored some freshness to the name.

 Among the celebs who dropped their birth name of Mary are Meryl Streep, Debbie Reynolds, and Lily Tomlin.

 For more detail on the origins and possible meanings of the name Mary, see this <a href="https://nameberry.com/blog/in-search-of-the-meaning-of-mary">excellent post on the subject</a>.

Mary

A melodious choice big in the sixties, Melody is now starting to pick up tempo again. It cracked the Top 150 for the first time ever in 2015. Melody is also the name of Ariel's equally curious and more tom-boyish daughter in The Little Mermaid sequel. Read more about Melody and other <a href="https://nameberry.com/blog/disney-princess-names">Disney Princess Names</a> in our featured blog.

Melody

The quality of mercy makes this lovely Puritan virtue name a quiet favorite today. Although it was most popular in the late nineteenth century, Mercy is on its way to a comeback -- it rose 143 spots between 2012 and 2013, making it one of the year's fastest-rising names. Right now, it's still stylish and distinctive, a rare and wonderful combination.
 Mercy is one of the characters with allegorical names in John Bunyan's A Pilgrim's Progress, and Mercy Pecksniff appears in Dickens's novel Martin Chuzzlewit with the nickname Merry. Mercy Lewis, in Arthur Miller's play The Crucible, was based on a real-life person, a witness at the Salem witch trials. Another historic Mercy is Mercy Warren, Revolutionary period patriot and writer of plays, books and poetry.
 Comic/sidekick Andy Richter, when he named his daughter Mercy, joked, "Just in case Puritanism comes back, we'll be ready with a real Puritan name"; Madonna renamed her Malawi-born daughter Mercy James. As a word name and modern virtue name, it's one of the most fashionable <a href="https://nameberry.com/baby-names/501/english-names-for-girls">English names for girls</a>.

Mercy

The bright, playful Micah feels like the middle ground between the safe, solid qualities of Michael and the flair and energy of Luca. Both Biblical and stylish, Micah is proving popular among parents today. 
A shortened form of Micaiah, Micah is an Old Testament name, meaning “who is like the Lord”. The biblical figure is a minor prophet who denounced oppression from the ruling classes and alternated between prophecies of doom and hope. 
Micah was among the Old Testament names revived by the Puritans in the 17th century, and it was used by early Pilgrim settlers in America. It wasn’t until the 1970s, however, that it really saw significant usage. 
Entering into the Top 200 back in the 80s, Micah has since made a slow and steady climb to the Top 100. Given to over 3000 boys – and 200 girls – each year, Micah now feels established but not overused. 
In pop culture, Micah has been used for characters in the animated series She-Ra: Princess of Power and in television show Heroes. It was also selected by Arthur Conan Doyle as the central character for his non-Holmes novel, Micah Clarke. 
Other noteworthy namesakes include Micah Hyde, an American football player, Micah Kogo, a Kenyan long-distance runner, and Micah Richards, an English footballer. Celebrities including actress Sarah Drew, basketball player Moses Malone, singer Lauryn Hill, musician Willie Nelson, and singer Neil Diamond all have sons called Micah. 
Popular in New Zealand and climbing the UK charts too, Micah makes a sleek but sparky choice for anyone honoring a Michael or wanting a name with history that still feels fresh. 
If you like Micah but prefer something outside the Top 100, or just want more inspiration, you could try a lesser-known <a href=“https://nameberry.com/list/456/unusual-biblical-baby-names”> Biblical name</a>, like Nekoda, Neriah, Tekoa, Zaccai, Ira, Jethro, or Jarah.

Micah

This form of the Biblical Rachel is well-used despite its somewhat counter-intuitive spelling which can make English speakers think the name should be pronounced with a k sound, as in Raquel.  The spelling may be inspired by Michael, but it's pronounced just like Rachel, with a soft ch. Lately it's on the decline, dropping more than 100 places in 2009 and leaving the US Top 1000 in 2013. 

Rachael

Samuel has been so popular for so long that it's hard to believe it's still climbing, at its highest point since the 1890s. 
 
This biblical name's popularity is somewhat propelled by the likability of the friendly nickname Sam, which returned to favor along with fellow former Grandpa names like Max and Gus. Sam is now often used on its own, for girls as well as boys.
 Samuel is derived from the Hebrew name Shemu’el, meaning "told by God." In the Old Testament, Samuel was one of the great judges and prophets of the Israelites, destined for a holy life from birth. He established the Hebrew monarchy, anointing both Saul and David as kings.
 
High-profile celebs who have chosen Samuel for their sons include Jennifer Garner and Ben Affleck, Jack Black, and Naomi Watts and Liev Schreiber, and Keri Russell and Matthew Rhys.

Samuel

The long-neglected name of Adam and Eve's third son after Cain and Abel, Seth is appreciated for its gentle, understated presence -- and strong middle-name potential. It reached a high of Number 63 in the year 2000.
 The name was adopted in England in the late Middle ages, then popularized by the Puritans after the Protestant Reformation.
 Seth was widely heard in the American old West, as reflected in such vintage TV oaters as Wagon Train, featuring Major Seth Adams. George Eliot and Charles Dickens both created characters named Seth and there is a Twilight werewolf called Seth Clearwater.
 Currently, Seth has taken on a lighter persona via such high-profile comical Seths as talk-show host Seth Meyers, the movies' Seth Rogen and animated-comedy creator Seth MacFarlane.

Seth

A solid classic with plenty of history, Thomas strikes the balance between strength and gentleness. A favorite in the UK, a staple in France, and Australia, and never absent from the US Top 100, Thomas feels like a safe bet and a name that fits into any era. 
The Greek form of the Aramaic name Ta’oma, Thomas means “twin.” It came about in the Bible because there were too many apostles called Judas, and so, Thomas became the “twin”, to reflect his close brotherhood with Jesus. 
Known as “Doubting Thomas” due to his initial skepticism of Jesus’s resurrection, he went on to become a martyr, and there was no need to doubt Thomas’s potential as a given name. 
Brought into common usage by the Normans, it was then always among the 5 most common English names for boys at any point between the 13th and 19th century. 
While it has fallen down the US charts in recent years, it remains a familiar and trusted choice. Given to over 6000 boys every year, it has made a steady climb back into the Top 50. 
Across the pond in the UK, both Thomas and Tommy make the Top 30, while Tom, Tommy-Lee and Tommie have made their mark in the Top 1000. 
As a well-established classic, Thomas naturally comes with plenty of noteworthy namesakes. “Thomas the Tank Engine” might appeal to you kids, but there’s also the theologian, Sir Thomas Aquinas, the cardinal Thomas Wolsey, the Founding Father, Thomas Jefferson. the philosopher, Thomas Hobbes, and the writer, Thomas Hardy. 
More recent namesakes for those who aren’t into history include actors Tom Hardy, Tom Cruise, and Tom Hiddleston, singers Tom Parker and Tom Fletcher, Olympic diver Tom Daley, and Thomas Sanders, of YouTube fame. 
A timeless all-rounder, Thomas comes with the intuitive nicknames, Tommy and Tom, which feel sweet for a child but not too cutesy for a grown-up. For more unexpected options, you could try the nature-inspired Moss or Scottish Tam. 
Unlikely to go out of style anytime soon, Thomas is a refined but approachable choice. If the popularity does give you pause, however, you could try the surname-inspired Thompson, or an <a href=“https://nameberry.com/list/492/100-classic-boys-names--below-the-top-1000/all”> underused classic</a> like Marius, Rufus, or Phinneas. 
Alternatively, there is a wealth of interesting variants to ponder, from Italian Tommaso and Scottish Tavish to Croatian Tomo– and for girls, there’s Thomasina, Tomine and Tamsin.

Thomas

namefreak218's list "Sibling Names for Charity" of 25 great name ideas: Aaron - Thomas!