teetotaller vs nondrinker

teetotaller and nondrinker both are nouns.

Word	Noun	Adjective	Verb	Adverb
teetotaller	Yes	No	No	No
nondrinker	Yes	No	No	No

As nouns, nondrinker is a hypernym of teetotaller; that is, nondrinker is a word with a broader meaning than teetotaller:

Other hypernyms of teetotaller include abstainer, abstinent.

teetotaller (noun)	nondrinker (noun)
a total abstainer	a person who refrains from drinking intoxicating beverages