Youthful or downy-bearded
A creative spelling of Jillian, which is the feminine form of Julian. It ultimately derives from the Roman family name Julius, which is thought to refer to being youthful or dedicated to the Roman god Jupiter.
Less common today
Jyllian isn't in the latest US Top 1000. It last peaked at #5,102 in 2001.
US births per 5-year period, 1990–present (SSA data).
