mule vs slipper

mule and slipper both are nouns.

Word	Noun	Adjective	Verb	Adverb
mule	Yes	No	No	No
slipper	Yes	No	No	No

As nouns, slipper is a hypernym of mule; that is, slipper is a word with a broader meaning than mule:

mule: a slipper that has no fitting around the heel
slipper: low footwear that can be slipped on and off easily; usually worn indoors

Other hypernyms of mule include carpet slipper.

mule (noun)	slipper (noun)
hybrid offspring of a male donkey and a female horse; usually sterile	low footwear that can be slipped on and off easily; usually worn indoors
a slipper that has no fitting around the heel	a person who slips or slides because of loss of traction