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.

Johanna is the version of this name used in Holland, Germany, and Scandinavia. The extra h makes Johanna a slightly more dignified version of Joanna.

Long common in Europe, the elegant and regal Juliana, also spelled with two n's, has invaded these shores, in tandem with the more classic Julia. Together with Julian, the name derives from Julius, a Roman family name. Its origin is shrouded in history, but possible roots include Latin iuvenis, meaning "youthfu"; Greek ioulos, meaning "downy-bearded"; or Jovis, a form of Jupiter, which means "sky father".

Joanna derives from the Greek name Ioanna, which in turn came from the Hebrew name Yohannah. It is featured in the New Testament as a woman who accompanied Jesus on his travels and eventually reached saint status. Other names related to Joanna include Joan, Joanne, Johanna, and Jana.

Jeremiah is a solid Old Testament prophet name that has gradually taken the place of the now dated Jeremy, Gerard and Gerald, joining other currently popular biblical 'iah' names like Josiah and Isaiah. In the Bible Jeremiah is a famous prophet whose story is recorded in the book named after him.

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.

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.

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.

Jerry is one of those short forms that, like Mike and Debbie, rose to popularity on the coattails of their formal versions. The equivalents today are nickname names like Ellie and Theo.

A variation of Jenson, which is actually more popular than the original in the United States. This spelling also holds the distinction of being the most common surname in Denmark.

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.

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.

This is a strong new James varietal, sometimes shared by girls. An original way to honor Grandpa Jim, Jameson is swiftly moving up the charts, entering the Top 100 for the first time ever in 2017. Jameson is one of the hottest boy names starting with J, still the most popular first initial for boys' names. One small caveat: Jameson is also a brand of whiskey.

Jerome has a bespectacled, serious, studious image, just like its namesake saint, who was a brilliant scholar. St. Jerome is the patron saint of students, librarians, and archaeologists.

This nickname for popular and traditional Joseph has a long history of being used as a given name all on its own. Nonetheless, everyone will always assume that Joey is short for the longer form. It might be nice for a potential son to have the option of a more professional and classic name to fall back on.

Probably due to its nursery rhyme association, Jill has the perpetual air of a rosy-cheeked tot -- even though it is one of the oldest names on the roster, a medieval variation on the Roman Julia. The pairing of Jack and Jill to connote a generic boy and girl goes back at least to the fifteenth century. But can knowing Jill's history keep it from sounding like a cute mid-twentieth century invention? There may be some possibility of Jill making it back up the hill.

Justin has been widely popular since the 1980s, when parents were seeking a fresher 'J' boys’ name to replace Jason, Jeremy and Jonathan. It's been dipping in popularity a bit in recent years but it reached as high as Number 9 in 1990. At this point it's Justin that is suffering from overexposure.

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.

Joe is still the ultimate good-guy name, not at all diminished by its longevity or popularity or its everyman rep as Regular Joe, Cowboy Joe, G.I. Joe, Joe Exotic, Joe Blow, Joe Millionaire, Average Joe — and now President Joe (Biden).

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.