drifter vs roamer

drifter and roamer both are nouns.

Word	Noun	Adjective	Verb	Adverb
drifter	Yes	No	No	No
roamer	Yes	No	No	No

As nouns, roamer is a hypernym of drifter; that is, roamer is a word with a broader meaning than drifter:

drifter: a wanderer who has no established residence or visible means of support
roamer: someone who leads a wandering unsettled life

Other hypernyms of drifter include have-not, poor person, bird of passage, rover, wanderer.

drifter (noun)	roamer (noun)
a wanderer who has no established residence or visible means of support	someone who leads a wandering unsettled life