idler vs bum

idler and bum both are nouns.

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

As nouns, idler and bum are synonyms defined as:

Other synonyms of idler include do-nothing, layabout, loafer.

idler (noun)	bum (noun)
person who does no work	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

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

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