wassailer vs drinker

wassailer and drinker both are nouns.

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

As nouns, drinker is a hypernym of wassailer; that is, drinker is a word with a broader meaning than wassailer:

Other hypernyms of wassailer include imbiber, juicer, toper.

wassailer (noun)	drinker (noun)
someone who enjoys riotous drinking	a person who drinks alcoholic beverages (especially to excess)
someone who who drinks to the health of someone or the success of some venture	a person who drinks liquids