drunkard vs drinker

drunkard and drinker both are nouns.

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

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

Other hypernyms of drunkard include imbiber, juicer, toper.

drunkard (noun)	drinker (noun)
a chronic drinker	a person who drinks alcoholic beverages (especially to excess)
	a person who drinks liquids