keister vs bum

keister and bum both are nouns.

Word	Noun	Adjective	Verb	Adverb
keister	Yes	No	No	No
bum	Yes	Yes	Yes	No

As nouns, keister and bum are synonyms defined as:

keister (noun)	bum (noun)
the fleshy part of the human body that you sit on	the fleshy part of the human body that you sit on
	a vagrant
	a person who is deemed to be despicable or contemptible
	person who does no work

keister (adjective)	bum (adjective)
	of very poor quality; flimsy

keister (verb)	bum (verb)
	ask for and get free; be a parasite
	be lazy or idle