sucker vs drinker

sucker and drinker both are nouns.

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

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

sucker (noun)	drinker (noun)
mostly North American freshwater fishes with a thick-lipped mouth for feeding by suction; related to carps	a person who drinks alcoholic beverages (especially to excess)
an organ specialized for sucking nourishment or for adhering to objects by suction	a person who drinks liquids
hard candy on a stick
flesh of any of numerous North American food fishes with toothless jaws
a drinker who sucks (as at a nipple or through a straw)
a person who is gullible and easy to take advantage of
a shoot arising from a plant's roots