Etymology

The Modern English word goat comes from the Old English gat which meant "she-goat", and this in turn derived from Proto-Germanic *gaitaz (cf. Old Norse and Dutch geit "goat", German Geiß "she-goat", and Gothic gaits "goat"), ultimately from Proto-Indo-European *ghaidos meaning "young goat" but also "jump" (cf. Latin haedus "kid", Old Church Slavonic zajęcǐ "hare", Sanskrit jihīte "he jumps").[4] To refer to the male of the species, Old English used bucca (which survives as "buck") until a shift to he-goat (and she-goat) occurred in the late 12th century. "Nanny goat" originated in the 18th century and "billy goat" in the 19th.