slipper vs mule

slipper and mule both are nouns.

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

As nouns, mule is a hyponym of slipper; that is, mule is a word with a more specific, narrower meaning than slipper:

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

Other hyponyms of slipper include bootee, bootie, scuff.

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