boozer vs drunkard

boozer and drunkard both are nouns.

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

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

Other hypernyms of boozer include drunk, inebriate, rummy, sot, wino.

boozer (noun)	drunkard (noun)
a person who drinks alcohol to excess habitually	a chronic drinker