Yak n. : A bovine mammal (Poephagus grunnies) native of the high plains of Central Asia. Its neck, the outer side of its legs, and its flanks, are covered with long, flowing, fine hair. Its tail is long and bushy, often white, and is valued as an ornament and for other purposes in India and China. There are several domesticated varieties, some of which lack the mane and the long hair on the flanks. Called also chauri gua, grunting cow, grunting ox, sarlac, sarlik, and sarluc.

Example:
What is the natural enemy of the Yak, other than humans?

Taxonomy
Yak, cattle, wild yak, Bos grunniens, hair, Tibetan, Bos taurus, Family Bovidae, species, yak skiing, yak polo, altitudes, International Yak Association, hybrids, free encyclopedia, meat, domestic cattle, Search.

Defination from the web:
... In addition to a large domestic population, there is a small, vulnerable wild yak population. ... In most languages which borrowed the word, including English, yak is usually used for both sexes. ...