n. 1 the offspring (usu. sterile) of a male donkey and a female horse, or (in general use) of a female donkey and a male horse (cf. HINNY(1)), used as a beast of burden. 2 a stupid or obstinate person. 3 (often attrib.) a hybrid and usu. sterile plant or animal (mule canary). 4 (in full spinning mule) a kind of spinning-machine producing yarn on spindles.
[ ME f. OF mul(e) f. L mulus mula ]