ox

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. An adult castrated bull of the genus Bos, especially B. taurus, used chiefly as a draft animal.
2. n. A bovine mammal.

Century Dictionary and Cyclopedia

1. n. The adult male of the domestic Bos taurus, known in the natural state as a bull, whose female is a cow, and whose young is a calf; in a wider sense, an animal of the family Bovidæ and subfamily Bovinæ or Ovibovinæ; a bovine. The several animals of this kind have each of them specific designations, as buffalo, bison, aurochs, zebu, musk-ox, etc.: the word is commonly restricted to the varieties of Bos taurus, the common ox, which is one of the most valuable of domestic animals. Its flesh is the principal article of animal food, and there is scarcely any part of the animal that is not useful to mankind: the skin, the horns, the bones, the blood, the hair, and the refuse of all these, have their separate uses. Having been specially domesticated by man from a stock which it is probably impossible to trace, the result has been the formation of very many breeds, races, or permanent varieties, some of which are valued for their flesh and hides, some for the richness and abundance of their milk, while others are in great repute for both beef and milk. Among the first class may be mentioned the Durham or shorthorn, the polled Aberdeen or Angus, and the West Highland or kyloe. Among the most celebrated for dairy purposes are the Jersey, Guernsey, Holstein-Friesian, Ayrshire, and Suffolk dun. For the purposes both of the dairy-farmer and of the grazier, the Hereford and a cross between a shorthorn and an Ayrshire are much fancied. The ox is used in many parts of the world as a beast of draft. The “wild ox.” now surviving in only a few parks, as at Chillingham Park in Northumberland, and at Cadzow Forest in Lanarkshire, seems, whatever its origin, to have been formerly an inhabitant of many forest-districts in Great Britain, particularly in the north of England and the south of Scotland.
2. n. In a restricted sense, the castrated male of Bos taurus, at least 4 years old and full-grown or nearly so. (See steer.) Such animals are most used as draft-animals and for beef.
3. n. Same as ox-coin.

Wiktionary

1. n. Any bovine animal used as a beast of burden or for food, especially an adult castrated male of the domestic species.

GNU Webster's 1913

1. n. (Zoöl.) The male of bovine quadrupeds, especially the domestic animal when castrated and grown to its full size, or nearly so. The word is also applied, as a general name, to any species of bovine animals, male and female.

WordNet 3.0

1. n. any of various wild bovines especially of the genera Bos or closely related Bibos
2. n. an adult castrated bull of the genus Bos; especially Bos taurus