The ancient German name Adelheidis gave rise to both Adelaide and Adelheid. While Adelaide is more popular and better known internationally, Adelheid is still used occasionally in Germany, the Netherlands, and Scandinavia. The German pronunciation is not that different from Adelaide, with a soft h and a long I sound instead of a long A in the last syllable.

Heidi originated as a short form of Adelheid.

Adelheid

Amory is best known for the hero of Fitzgerald's 1920 This Side of Paradise, Princeton student Amory Blaine. Amory is in some danger of being borrowed by the girls, a la Avery. Alternate spellings Amori or Amorie also relate to the Latin word for love.

Amory

Ansel, primarily associated with the great western photographer Ansel Adams, famed for his magnificent photographs of the Yosemite Valley, could make a creative artist-hero choice. For Adams it was a family name – he was named after his uncle, Ansel Easton. And, in turn, Adams was the namesake of young heartthrob Ansel Elgort, son of a photographer.
 Derived from the same root as Anselm, Ansel is a medieval Germanic name that still feels fresh and stylish today.
 Ansel has been far from a <a href="https://nameberry.com/list/317/unique-baby-names">unique baby name</a> – it was on and off the popularity lists in the late nineteenth and early twentieth centuries, reaching as high as Number 540 in 1893.

Ansel

Muscular German name that never fully assimilated into American culture.

Egon

Though she has long stood on her own, Elke has many longer cross-cultural connections, to the Dutch/German/Scandinavian Adelheid and Alice and the English Adelaide, as a feminine version of Elkanah and as a Yiddish form of Eleanor.
 The name became best known in the U.S. via the Berlin-born Elke Sommer,a popular actress and pin-up girl in the 1960s.

Elke

The superpopularity of Emily and Emma has recently boosted the unisex Emery, especially since it became a celebrity baby name when it was chosen by Angie Harmon and Jason Sehorn. 

Emery now ranks among the girls' Top 100 names in the US, though Emma, Emily, and even Emilia are more popular. Emerson and Emmeline are two other popular girl names in the same vein.

Nickname Emmy or Emmie makes it cute and girlish but even more popular given the legion of little Emmys.

Emery

Faber

A German name with little chance of American adoption. 

Haldis

Hannele

Those "Where's Gretel?" jokes will get old pretty fast.

Hansel

Harmon

Some music-minded parents might consider this especially as a middle name, to honor the great Austrian composer. 

Haydn

Howard, once hugely popular -- in the Top 50 from the 1870s to early 1950s, hitting Number 24 in 1920 -- has been stuck in Dad-Grandad limbo for decades, but is showing some signs of stirring back to life. Along with such formerly-fusty names as George and Harold, Howard may soon feel baby-appropriate, perhaps with the short form Ward.
Howard was the surname of an early English noble family, gradually metamorphosing into a first name in the nineteenth century. Notable Howards include tycoon Howard Hughes, director Howard Hawks, politician Howard Dean, and media figure Howard Stern. In literature, there is Ayn Rand's iconic architect Howard Roark, protagonist of The Fountainhead.
 Strange trivia item: Vampire novelist Anne Rice's given name is Howard Allen. She has said her mother "had the idea that naming a woman Howard was going to give that woman an unusual advantage in the world."

Howard

Ivo is an unusual, catchy name with the energetic impact of all names ending in 'o'. Hardly heard in the U.S., it is used a bit more frequently in England, as is the related Ivor, a favorite of such novelists as Evelyn Waugh and P.G. Wodehouse. Ivo is currently most popular in the Netherlands.

Kaiser, as in roll and Wilhelm, appeared for the first time on the US Top 1000 in 2017.  It fits the two-syllable -er ending style that's all the rage, and it lends itself to the short form Kai.  But we hope this Germanic version of what is essentially a title rather than a name doesn't keep rising on the charts.

Kaiser

Levin, known in the U.S. mostly as a surname, is a Top 100 boys' name in Germany.  There have been saints with variations of this name, whose meaning relates to love.

Levin

Once restricted to evangelical Protestants honoring the ecclesiastical reformer and theologian Martin Luther, leader of the Protestant revolution. In more recent times it has been favored by parents wishing to honor civil rights hero Martin Luther King Jr. Luther was a Top 100 name at the turn of the last century, but fell off the list in the early 1990s. 
 <br?>Luther Burbank was an eminent botanist and Luther Vandross was a popular R&B artist. It's the name of a main character on the Disney series Zeke and Luther. The name was given a shot of contemporary energy via Idris Elba's dynamic performance in the eponymous BBC crime drama.

Luther

Matilda is a sweet vintage name that has been gently climbing the popularity list for the past 15 years, after a half-century slumber. The spunky children's book heroine Matilda is one factor in its rise, along with others of its class like Eloise and Caspian.

The comeback of this sweet vintage name, one of the most stylish girls' names starting with M, has been prompted by a boomlet of starbaby Matildas, beginning with chef Gordon Ramsey's in 2002 and Moon Unit Zappa's two years later. But the renaissance of this name of the charming Roald Dahl heroine was assured when Michelle Williams and the late Heath Ledger chose Matilda for their daughter. 
 Matilda was introduced to the English-speaking world by the eleventh century Matilda of Flanders, queen of William the Conqueror, then used for his granddaughter, known as Maud. In literature, Matilda appeared in Dickens's Nicholas Nickleby.
<p.>Trivia tidbit: The Matilda in the Australian song 'Waltzing Matilda' refers not to a person but to the knapsacks that swing, or waltz, on the backs of itinerant laborers as they walk along.
 Highly popular in England and Australia, Matilda has a choice of great nicknames: Tillie for the bold, Mattie for the shy, Tilda for the slightly more eccentric, such as Tilda Swinton, born Katherine Matilda.
 Molly Ringwald used the spelling Mathilda for her daughter.

Matilda

With Matthew sounding somewhat exhausted, and ancient endings sounding new again, this New Testament apostolic name makes an appealing and recommended choice. Both Mathias and Matias are well used in the Hispanic community, and throughout Europe. Will Ferrell and his Swedish wife chose Matias for their second son.
 In the Bible, Matthias is the apostle chosen to replace Judas Iscariot. The Catholic and Eastern Orthodox churches honor Matthias as a saint.
 The Mathias spelling is used by George Eliot for the father of the protagonist of her novel Adam Bede.
 Matthias is popular abroad, and especially in Austria, France, The Netherlands, Iceland and Belgium, where it is normally pronounced Muh-TEE-us, though Americans are more likely to say Mah-THY-us.

Matthias

Miles, which has a permanent veneer of cool thanks to jazz great Miles Davis, is a confident and polished boys' name that's an American classic. Always ranking in the US Top 1000, it's been drifting up the charts for the past half century but has never been TOO popular.
 
Miles is a favorite of celebrity baby namers, given to their sons by Elisabeth Shue, Mayim Bialik, Larenz Tate, Joan Cusack and Lionel Ritchie. It also makes a great honor name for all the Grandpa Michaels out there.
 Miles was the name of the first translator of the Bible into English--the English monk Miles Coverdale, which is also the name of a character in Hawthorne's The Blithedale Romance. Miles Hendon figures in Mark Twain's The Prince and the Pauper, and Miles was one of the young children in Henry James's The Turn of the Screw. Miles--or Myles--Standish was the leader of the Pilgrim fathers.
 Miles has also been a favorite movie and TV character name from the days of Murphy Brown to 24 and Avatar.

Miles

Cute tomboyish diminutive that's popular in Germany but has not spread far.  An interesting choice for the parent who wants an elaborate feminine proper name with a modern short form.

Neele

If you love Dixie, Trixie and Pixie, this name of a mermaid-like sprite in German folklore may be for you.  It might also make an update for Nicki.

Nixie

Odila

Most famous as the name of King Pepin the Short, this choice might feel somewhat belittling.   The even-shorter form is Pippin, a name adopted for musical theater, and the Dutch form Pepijn is in that country's Top 100.

Pepin

European royal name, and to Americans a place-name evoking the majestic mountain in Washington state. 

Rainier

Severin is an ancient Roman family name borne by several early saints. It's still alive throughout Europe, and could be ready for import here. Severin Winter is a wrestling prodigy character in John Irving's The 158-Pound Marriage and, in its original Latin form, Severus Snape appears in Harry Potter.

Severin

Also spelled Zilke, Silke is a common short form for variations of Cecilia and Celia found in Germany.

Silke

Theodor

A straightforward, down-to-earth nickname many Walters, from Whitman to Disney, have chosen to go by. 

Walt

Zinnia is an unusual floral choice with a bit more edge and energy than most and beginning to find its way onto namers' wish lists of botanical possibilities. Named after an eighteenth German botanist called Johann Gottfried Zinn, it appears in Roald Dahl's Matilda as the young protagonist's mother.
 In the language of flowers, Zinnias symbolize remembrance.

Zinnia

Ziska

madeliner's list "German Favorites" of 31 great name ideas: Adelheid - Ziska!