At the height of the Jennifer craze, many parents were cutting straight to the nickname and putting Jenny on the birth certificate. But now that Jennifer is the mom rather than the daughter, Jenny, which has been somewhat replaced by Jenna, has faded as well.

A sweet name with many cross-cultural ties: it's an equivalent of Jane in languages including Czech, Slovak, Dutch, German, Slovene, Catalan, Estonian, and Latvian.

Jackie Kennedy gave this name a lot of style, but it doesn't seem destined for a comeback the way brother name Jack has. Jackie and Jacqueline both peaked in 1961.

Jen is a short, crisp feminine name that originated primarily as a diminutive of Jennifer, though it can also be a nickname for names like Jenna, Jenny, or Genevieve. The root name Jennifer comes from the Welsh 'Gwenhwyfar,' meaning 'white wave' or 'fair spirit.' Jen gained independent usage during the 1970s and 1980s when Jennifer was at peak popularity, with some parents choosing to put just 'Jen' on the birth certificate. Its simplicity and directness appeal to those preferring unpretentious, straightforward names. While Jen's popularity as a stand-alone name has declined since the 1990s, it maintains appeal for its brevity and friendly, approachable quality. The name carries a casual confidence and remains recognizable without being overly common as a formal name.

Jagger is a swaggering Rolling Stone of a name that's been picked up by a number of fellow celebs, including Lindsay Davenport and Brett Scallions--while Soleil Moon Frye pulled a gender switch when she bestowed it on her daughter. It's edgy with a touch of danger.

Streamlined version of the classic boys' names, sometimes a short form of Jonathan, which is in fact an entirely different name from John attached to a different Biblical personage. Jon feels more modern than the traditional John, but some may find it an overly slight variation on an already slim name. Jon Snow is a popular character on HBO's Game of Thrones.

Peaked in the 1940s, but still an amiable classic, a la Joe and Tom -- though rarely used on its own.

Cowboyish short form that's both macho and cool. Got prime time exposure on The West Wing.

The Jodie spelling might be even more obscure, at this point, than the fading original, except actresses Jodie Foster and Jodie Sweetin have kept it in the public eye.

Juan, the Spanish version of John, is ubiquitous in the Spanish-speaking world, and is familiar internationally via such references as Don Juan and San Juan.

This variation of Jordan entered the Top 1000 in 1989. Jordyn as well as Jordan trended throughout the 90s and early 2000s, but are beginning to fall slightly on the girls' side. While the Jordan spelling reached the highest point in popularity out of the 2, making it into the Top 50 in the late 90s and early 2000s, today Jordyn has taken the lead.

The line should end with Junior Soprano. While most would expect this to be a nickname rather than an actual given name, Junior has always ranked in the US Top 1000, hitting its peak in 1925 at Number 116.

Thanks to two cultural influences, January has joined March, April, June and August as a plausible month name.

Though every Spanish student knows that the male classic is pronounced HY-me, for girls this is a straight homonym for Jamie, a favorite ambisexual 1970s nickname name. Another way to think of it is as a variation of the French "J'aime" (meaning I love).

With Old European vibes, Johan is a variant of the classic John, similar to the Latin, Hebrew, and Germanic forms, Iohannes, Yohanan, and Johannes. Conjuring up the image of the classical composer Brahms or the astronomer Kepler, while still feeling timeless and distinctive, Johan has been in the US Top 600 for most of the 21st century, helped along by Heidi Klum and Seal using it for their son in 2006.

Both Jeb and Jed are very attractive Old Testament short forms with long and bright futures. Jeb's main current association is with the Bush brother and former governor of Florida, but the name was a mainstay on early TV westerns, and then went upscale as the nickname (his birth name being Josiah) of the President on "The West Wing."

A Jada alternative that has lost ground this decade after peaking around 2010.

Justice is a fashionable word name, used for both girls and boys. Justice has the distinction of being a virtue name without the religious implications of Faith or Grace. It still feels more male than female, perhaps partly due to the classic Roman name Justus, but Justice has become a more common pick for girls in recent years.

This once obscure name was propelled to fame by Britney Spears, and by Will and Jada Pinkett Smith in the 2000's. It skyrocketed into the US Top 10 for boys, but it also saw significant use for girls.

Once rare, this streamlined form of Jessica has been boosted by two very different television figures: the Jemima Kirke character on HBO series Girls, and reality television daughter Jessa Duggar.