Has a slight aura of danger, from its being two types of weapons and a looming character in the Star Wars films. Best left as a nickname for Mason. 

Mace

Mara is the evocative ancient root of Mary, appearing in the Book of Ruth, in which Naomi, devastated after the death of her two sons, says "Call me not Naomi, call me Mara." It's one of the <a href="https://nameberry.com/search/girls-names/m">girl names starting with M</a> that both fits in and stands out.
 Mara is a multicultural name, also a Kiswahili word meaning "a time," and could be conceived as a geographical name, being a river flowing through Kenya and Tanzania.
 As a child actress, Mara Wilson played leading roles in Matilda and Mrs. Doubtfire.

Mara

Max was derived from Maximilian, a Latin name that originated from the Roman family name Maximus. The character name Max in the children's classic Where the Wild Things Are had an impact on baby namers. Max is a widely used name internationally.
 
Max was transformed from cigar-chomping grandpa to rosy-cheeked baby in the 1980s, along with card-playing partners Sam and Jake. Never quite as popular as it seemed, Max is now close to the the highest it's been on the Social Security list since 1917, after which German-sounding names went out of favor. 
 
Max has been a popular starbaby name for decades, most recently for the sons of Christina Aguilera, Cynthia Nixon and Charlie Sheen, while other celebs, such as Jennifer Lopez and Marc Anthony, have used more formal appellations--Maximilian, Maxwell, Maxfield--on the birth certificate to get to the nickname Max. Skater Scott Hamilton put his own spin on it by maximizing the spelling of his son's name to Maxx.
 
Warning: Max has long been among the <a href="https://nameberry.com/popular-names/dogs">most popular dog names</a>.

An unusual nickname for unusual names — Mazikeen, a name invented by Neil Gaiman for his Sandman comics, and Mazarine, a French color name.

Meena

Most famous as a Dracula victim (where Mina is short for Wilhelmina), Mina is a name that can stand on its own or be a diminutive of any name ending in -mina, most usually Wilhelmina.
This Old World German nickname name was popular in the US in the 19th century, then dropped from sight after World War II along with many other German names. That's turned around in the last 20 years, and Mina is now heading up the charts again.
Mina is also a nickname name that has its own nickname, Minka, used in many European countries and occasionally in the US, though usually identified as Polish.
Mina Loy was a modernist artist and writer who associated with the likes of T.S. Eliot, Ezra Pound, and Gertrude Stein.

Mina

Morgan has long been a traditional Welsh male name, a variant of the Old Welsh name Morcant, from the Welsh elements mor, meaning "sea" and cant, "circle." The female Morgan is unrelated to the male version—it is a name from Arthurian legend created for Morgan le Fay, King Arthur's half-sister and famed sorceress. Her name comes from Morgen, an Old Welsh name meaning "sea-born," and is related to the Irish name Muirgen. 
 
In this country, Morgan is now used more for girls than boys, though considerably lower than its Top 25 status in the 1990's. And although it's been veering south for both sexes, we still find Morgan a sophisticated choice. 
 
Actress Morgan Fairchild—who had an influence on the name's popularity for girls—was born Patsy.

Morgan

Maul

Miraj

Moralo

Mundi

Naberrie

Neeku

Numa

Orson has had in the past a rotund teddy-bear image, a la Orson Welles, who early on dropped his common given name of George in favor of his more distinctive middle one, and who seemed to own it during his lifetime. No longer a single-person signature, it's now an interesting possibility for any parent seeking an unusual yet solid name. It's started to appear to the celeb set--both Paz Vega and Lauren Ambrose have little Orsons.
 The comic actor Orson Bean was born Dallas; there was a Desperate Housewives character called Orson Hodge.
 There's also a fifteenth century story about two brothers named Valentine and Orson, in which the latter was carried off by a bear and raised as one of its cubs.

Orson

Owen, a resonant Celtic name, has ranked among the Top 100 boys' names in the US for 20 years and is now at its highest point ever.
 
Why do so many parents love Owen? It's a classic with a genuine history, yet it's right in step with the modern trend for two-syllable, n-ending boys' names. Owen-like choices with less tradition behind them include Logan, Bowen, and Rowan.
 Owen is derived from two names—the Welsh Owain and the Celtic Eoghan. Each are connected to Eugene, which ultimately came from the Greek word eugenes, comprised of the elements eu, meaning good, and genes, "born." 
 
Owen became a Welsh patronymic surname during the Renaissance. The legendary St. Owen was a Benedictine monk who was a follower of St. Chad.
 
In Ireland, Owen may be spelled Eoin, as in Irish writer Eoin Colfer, and Eoghan. Other similar names include the Scottish Ewan or Euan and the French Ouen.
 
Owen's popularity now extends beyond English-speaking countries to France, Belgium, and the Netherlands.

Owen

Obi-Wan

Offee

Ohnaka

Oola

Orrelios

Carasynthia's list "Star Wars M-O Girl and Boy Names" of 22 great name ideas: Mace - Orrelios!