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.
Etymology: ME f. OF mul(e) f. L mulus mula
2.
n. a light shoe or slipper without a back.
Etymology: F
3.
var. of MEWL.
Useful english dictionary. 2012.