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, associated with youthfulness and vitality.
Less common today
Jillyan isn't in the latest US Top 1000. It last peaked at #6,039 in 1999.
US births per 5-year period, 1990–present (SSA data).
