slipper vs bootie

slipper and bootie both are nouns.

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

As nouns, bootie is a hyponym of slipper; that is, bootie 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
bootie: a slipper that is soft and wool (for babies)

Other hyponyms of slipper include bootee, mule, scuff.

slipper (noun)	bootie (noun)
low footwear that can be slipped on and off easily; usually worn indoors	a slipper that is soft and wool (for babies)
a person who slips or slides because of loss of traction