US Popularity Rank: 2140

Origin: Latin

Meaning: Youthful; Downy-bearded

Jillian, which has Latin and Greek origin. Meaning "youthful," in Latin, it's perfect for reminding baby that they'll always be, well, your baby. This girl's name can also be spelled as Gillian and has the retro-sounding Jill as a nickname. Jillian is the feminine form of Julian or Julius, which means "downy-bearded" in Greek and is also intrinsically linked to some of the Roman Empire's most powerful rulers.