noun a very stubborn person.
2. mule ·noun a hybrid animal; specifically, one generated between an ass and a mare, sometimes a horse and a she-ass. ·see hinny.
3. mule ·noun a plant or vegetable produced by impregnating the pistil of one species with the pollen or fecundating dust of another;
called also hybrid.
4. mule ·noun a machine, used in factories, for spinning cotton, wool, ·etc., into yarn or thread and winding it into cops;
called also jenny and mule-jenny.