emphasis For donkey's years means for a very long time. I've been a vegetarian for donkey's years. = ages. or burro Descendant of the African wild ass that has been used as a beast of burden since 4000 BC. The average donkey stands about 40 in. (100 cm) high at the shoulder, but breeds range from 24 to 66 in. (61-168 cm). Coats range from white to gray or black, usually with a dark stripe from mane to tail and a crosswise stripe on the shoulders. The mane is short and upright, and the tail has long hairs only at the end. The very long ears are dark at the base and tip. Donkeys are surefooted and can carry heavy loads over rough terrain. See also mule
A donkey is an animal which is like a horse but which is smaller and has longer ears. = ass