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.

Though this feels like a modern invention, Jay has been in use for centuries. Early Jays often were named in honor of founding father John Jay, whose surname derived from the jaybird. A popular mid-century choice, Jay was in the Top 100 from 1956 to 1970. In the last couple of decades he was replaced by such more elaborate forms as Jayden, Jaylen, and Jayce. But Jay could make a comeback in tandem with cousins May, Kay, Fay, and Ray.

Jocelyn has gotten new life and popularity as a result of the current passion for lyn endings. Though it was a male name in medieval times, now Jocelyn couldn't sound more softly feminine.

Jared is an Old Testament name that has been popular for decades--it was revived in the sixties via TV westerns-- and is still an appealing option.

Joy is from an older generation of word names, which also included Merry, Bliss, and Glory -- all of which exert a certain amount of personality pressure on a child. However, Joy, like Grace, Hope, and Rose, has crossed more into name-territory than other word choices, which lightens some of that pressure.

While Jadon is the authentic biblical name, Jaden is by far the more popular spelling, first noticed when Will and Jada Pinkett Smith used it for their now grown (and famous) son. It has since swept the country for both sexes, with a wide variety of spellings and rhyming cousins.

Immortal through its association with the ancient Caesar (it was his clan name), Julius may still lag behind Julian, but is definitely starting to make a comeback, and in fact feels more cutting edge, in line with the current trend for Latin -us endings.

This unpretentious, accessible, and optimistic ("everything's jake" -- meaning OK) short form of the top name Jacob is itself widely used, though more parents these days are opting for the full name Jacob. Jake (born Jacob) Gyllenhall is its most prominent current bearer.

The ultimate midcentury nickname, retaining a good measure of retro charm, was chosen for her son by Mira Sorvino.

Some people may prefer this spelling to clarify the name's connection to John, but it could be one h too many, exemplified by its steady decline over the past two decades.

A modern invention that's been in use since the 80s and in the charts since the 90s, which combines the sounds of Jasmine (or Jasper or just the word jazz) with the popular suffix, -lyn. Inspiration might also have come from Joslyn, Jocelyn, or Roslyn. Trendy but snazzy too, Jazlyn remains in the US Top 600.

The mostly Americanized version of Geoffrey was a trendy mid-century hit, with nickname Jeff the epitome of cool. Jeffrey entered the pop list in 1934 and was a Top 20 name from the mid-fifties to 1978.

Jacqueline originated as a feminine form of Jacques, the French variation of James, and therefore Jacob. Jacob was ultimately derived from the Hebrew name Ya’aqov, and gets its meaning, "supplanter" from the story of Jacob supplanting his brother Esau as the first-born son in the Bible. Jacqueline was first used in France in the Middle Ages.

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.

The cool form of James in the 1970s and '80s for both sexes. Still a more stylish short form than Jimmy, though many parents will want to call James by his entire, not-very-long name.

Originally used for children baptized in holy water from the river Jordan, it became one of the leading androgynous names of the nineties. As the balance tips toward the boys' side, it's slipping on the girls' popularity chart. Alternate spelling Jordyn is now more popular for girls.

Jennifer is the Cornish variation of Guinevere, which ultimately derived from the Welsh name Gwenhwyfar. As such, it is connected to the queen of Arthurian legend, and sharees the same meaning of "white shadow", "white wave", or "white phantom".

Jonas has a slightly more grandfatherly image than the English version of his name, but that only adds to its retro appeal. And though it may lag behind Jonah in this country, Jonas is riding a huge wave of popularity in Europe, where it ranks highly in Germany, Switzerland, Austria and Norway.

When Jennifer finally gave up her Number 1 place on the girls' popularity list, her crown was passed to Jessica, who reigned for not one but two decades. Jessica was the Number 1 name in both the mid-1980s and 1990s, never sounding quite as trendy as its predecessor, maybe because of its classic Shakespearean pedigree.

Jenna was first noted on the 1980s TV series Dallas, later associated with one of the First Twin Daughters. Jenna is still being used, but no longer feels much fresher than Jennifer. You can also spell it Jena, but then many people will pronounce it jeen-a, as in Gina.