daydreamer vs bum

daydreamer and bum both are nouns.

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

As nouns, bum is a hypernym of daydreamer; that is, bum is a word with a broader meaning than daydreamer:

Other hypernyms of daydreamer include do-nothing, idler, layabout, loafer.

daydreamer (noun)	bum (noun)
someone who indulges in idle or absentminded daydreaming	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

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

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