westerner vs weeaboo

westerner and weeaboo both are nouns.

Word	Noun	Adjective	Verb	Adverb
westerner	Yes	No	No	No
weeaboo	Yes	No	No	No

As nouns, weeaboo is a hyponym of westerner; that is, weeaboo is a word with a more specific, narrower meaning than westerner:

westerner: an inhabitant of a western area; especially of the U.S.
weeaboo: A white person, who is obsessed with Japanese culture, usually pejorative

Other hyponyms of westerner include weeb.

westerner (noun)	weeaboo (noun)
an inhabitant of a western area; especially of the U.S.	A white person, who is obsessed with Japanese culture, usually pejorative