[Tibetan.] A large ox, very sure-footed, found in the plains of Central Asia. It is like the long-horned Scottish cattle, but more strongly built. In color it is black, and it has long hair, especially at the hind quarters, where it touches the ground. The wild yak is found always just under the snow-line ; the tame yak is seldom employed below 12,000 feet above sea-level. The tails of domestic yaks are employed in India as fly-flaps.