Synonyms for Billy goat:

n.

boar, boy, bull, dog, bullock, cockerel, alpha male. billy goat (noun)
billy, he-goat.
sire (noun)
buck, goat.

Other synonyms:

buck, goat, alpha male, boar, bull, bullock. dog. boy. Other relevant words:
boar, buck, bull, dog, bullock, cockerel, goat.