Dictionary entry

Filly

Webster's Dictionary 1913

Fil″ly (?), n.; pl.Fillies (#). [Cf. Icel. fylia, fr. foli foal. See Foal.] 1. (Zoöl.) A female foal or colt; a young mare. Cf. Colt, Foal.

Neighing in likeness of a filly foal. Shak.

2. A lively, spirited young girl. Addison.