n.; pl. Fillies [ Cf. Icel. fylia, fr. foli foal. See Foal. ] 1. (Zool.) A female foal or colt; a young mare. Cf. Colt, Foal. [ 1913 Webster ]
Neighing in likeness of a filly foal. Shak. [ 1913 Webster ]
2. A lively, spirited young girl. [ Colloq. ] Addison. [ 1913 Webster ]