dosser vs bum

dosser and bum both are nouns.

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

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

Other hypernyms of dosser include hobo, tramp.

dosser (noun)	bum (noun)
someone who sleeps in any convenient place	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

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

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