- a young female horse, specif. one under five years of age
- Informal a vivacious young woman or girl
Origin of fillyMiddle English filli from Old Norse fylja, feminine of foli, foal
- A young female horse, especially a racehorse less than five years old, or a young female of another equine species.
- Informal A lively, high-spirited girl or young woman.
Origin of fillyMiddle English filli from Old Norse fylja ; see pau-1 in Indo-European roots.
- A young female horse.
- (dated) A young attractive female.
- Hey, Homer, get a load of the gams on that filly!
From Old Norse fylja (whence Danish føl).