Cleo, one of the few girls' names to boast the cool-yet-lively o ending, is of course short for Cleopatra, the name of one of the most powerful women in history.

Indigo is one of the most appealing and evocative of the new generation of color names. Color names have joined flower and jewel names -- in a big way -- and Indigo, a deep blue-purple dye from plants native to India, is particularly striking for both girls and boys. Although most people don't think of it like this, Indigo might also be considered among the most stylish Greek baby names in use today. Some cultural references: The Indigo Girls are a folk duo, 'Mood Indigo' is a classic Duke Ellington jazz composition, and there is a 1970's New Age theory that Indigo children possess special, sometimes supernatural abilities. Indigo is the name of a character in the Ntozake Shange novel Sassafrass, Cypress & Indigo, and was used for his daughter by Lou Diamond Phillips.

Leo is of course a very popular name for boys and an equally rare one for girls. But 28 baby girls were named Leo in the US last year, and as feminine leonine names such as Leonora and Leonia find more widespread popularity, Leo is popping up as an adorable short form for girls as well as boys.

Arlo, an unexpectedly popular name for boys these days, is also finding new life as a girls' name. Its roots are primarily as an Irish or English surname, but it might also be a short form of the Spanish Carlos or Italian Carlo, forms of Charles.

Marlo first came to prominence as a perky, pretty nickname name that seemed to have been invented by or for Marlo Thomas, who was born Margaret. But Marlow and Marlowe are English surnames meaning driftwood, are more popular forms of the name, giving it historical depth and a nature meaning. And Marlo is the most truly gender-neutral, given to about 100 babies of each sex last year.

Juno is a boy's name of Latin origin. Traditionally known as the Roman goddess of marriage and childbirth, Juno has crossed gender boundaries to become a distinctive masculine choice. The name carries associations with protection, vitality, and leadership. While relatively uncommon for boys, it has a strong, concise sound with its two syllables ending in a resonant 'o' that feels both classical and contemporary. Juno has gained some visibility through cultural references, including the popular film 'Juno,' though that featured a female protagonist. As parents seek unique names with historical roots, Juno offers boys a name with gravitas and a touch of mythology.

Coco came to prominence as the nickname of the legendary French designer Chanel (born Gabrielle) and has lately become a starbaby favorite, initially chosen by Courteney Cox for her daughter Coco Riley in 2004. At first it was the kind of name that the press loves to ridicule, but we predict Coco's heading for more broad acceptance and even popularity.

A biblical place name with trumpeting verve and strength.

This hyper-rhythmic name has two evocative references. In Greek mythology, she was an island nymph, a daughter of Atlas, who delayed Odysseus from returning home. It is also a genre of West Indian music, originating in Trinidad and Tobago and largely popularized in the States by Harry Belafonte.

Rio is one of Japan's most popular girls' names, constantly sitting in that country's Top 10. Of course, Rio may also stem from the Portuguese and Spanish word for river, and the Brazilian city Rio de Janeiro. A truly international name for a cosmopolitan baby!

One of those ultimate cool-girl names, played by Keira Knightley in a movie about a supermodel-turned-bounty hunter, but kids might associate it with the game. High profile British designer India Hicks used it for her daughter. As a girls' nameit's still very rare, used in 2015 in the US for only seven baby girls.

Theo has a girls' name is used for only a handful of babies today. As a short form of Theodora, Theo is used much less frequently than Thea or even Teddy. One notable appearance was as the younger daughter in Sofia Coppola's film On the Rocks in 2020.

Like Araceli, Cielo is a heavenly name associated with the Virgin Mary. Cielo, the Spanish word for "sky," began being used as a name in honor of María del Cielo, a title for the Virgin Mary meaning "Mary of the Sky."

The name Jo still evokes the spunky image of the character in Louisa May Alcott's Little Women. Its literary status makes Jo one of the OG boyish nicknames for girls, ala Frankie, Billie, and Stevie. If you like that form, you can lengthen it to Joey.

Sweet Japanese choice.

A much more dynamic nickname than Nicky for any of the Nic-names. Part of a growing trend of boyish nicknames for girls - alongside Stevie and Lou - Nico has cheerful, snappy sounds, and a fresh, sassy image.

This tiny but punchy name has multiple origins. It stands strong alone, but could be short for numerous names including Bonnie and Bodhi. In Mandarin Chinese, Bo means "wave".

This name, which refers to Mary as the Virgin of the Dew, is all but unknown in the Anglo community, but popular enough in Hispanic families that it made the US Top 1000 until least until 2006. Also spelled Rocío, it remains popular in Spain and Chile, where it ranks in the Top 100.

Ro is a casual short form that doesn't usually appear on the birth certificate on its own. But it makes a friendly nickname for any girls' name starting with Ro-.

Upper-crusty nickname occasionally used in Britain, particularly in 1930s novels featuring significant garden party scenes, but eclipsed here by Carrie et al.