drinker vs quaffer

drinker and quaffer both are nouns.

Word	Noun	Adjective	Verb	Adverb
drinker	Yes	No	No	No
quaffer	Yes	No	No	No

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

Other hyponyms of drinker include gulper, guzzler, sipper, sucker.

drinker (noun)	quaffer (noun)
a person who drinks alcoholic beverages (especially to excess)	a person who drinks heartily
a person who drinks liquids