One of the numerous fine and generally cylindrical filaments that grow from the skin or integument of animals, esp. of most mammals, of which they form the characteristic coat; applied also to similar-looking filamentous outgrowths from the body of insects and other invertebrates, although these are generally of different structure.——牛津当代大辞典

one of the long fine things like thread that grows on people’s heads and on other parts of their bodies, or similar things that grow on animals.——朗文当代大辞典  @en