Other forms: fillies
A filly is a young female horse. A yearling filly, the filly won, a fast filly.
In racing the word has a precise cut-off: a female horse is a filly until she turns four and a mare after that, and a male is a colt then a horse. Some of the great races are for fillies only. It comes from the same Old Norse root as foal.
1nounfillyA young female horse.
“The mare gave birth to a healthy filly in the spring.”
filly is a horse.
Old Norse fylja means a young female horse, related to foal. The word replaced no native English term.
Proto-Indo-European
*peh₂w-
Old Norse
fylja
English, today
filly
From Old Norse fylja (whence Danish føl), related to a doublet of foal. Cognate with Dutch veulen, German Fohlen.
Etymology from Wiktionary, CC BY-SA