footwear vs slipper

footwear and slipper both are nouns.

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

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

footwear: covering for a person's feet
slipper: low footwear that can be slipped on and off easily; usually worn indoors

Other hyponyms of footwear include boot, clog, geta, patten, sabot, flats, overshoe, shoe, carpet slipper.

footwear (noun)	slipper (noun)
covering for a person's feet	low footwear that can be slipped on and off easily; usually worn indoors
clothing worn on a person's feet	a person who slips or slides because of loss of traction