Ox - (Webster's 1828 Dictionary)
OX, n. plu. oxen. pron. ox'n.
The male of the bovine genus of quadrupeds, castrated and grown to his size or nearly so. The young male is called in America a steer. The same animal not castrated is called a bull. These distinctions are well established with us in regard to domestic animals of this genus. When we speak of wild animals of this kind, ox is sometimes applied both to the male and female, and in zoology, the same practice exists in regard to the domestic animals. Sop in common usage, a pair of bulls yoked may be sometimes called oxen. We never apply the name ox to the cow or female of the domestic kind. Oxen in the plural may comprehend both the male and female.