noun
Refers to a person who drinks a lot of alcohol, often habitually. Neutral in register but can carry a slightly negative connotation depending on context.
彼はかなりの飲み手で、毎晩日本酒を何合も空ける。
He's quite a heavy drinker and empties several cups of sake every night.
あの人は酒豪というより、ただの飲み手だ。
That person is not so much a strong drinker as just a heavy drinker.
酒豪 implies a strong, impressive drinker who can hold their liquor well, often with a positive or admiring nuance, while 飲み手 simply means a heavy drinker without the connotation of strength or skill.
飲んべえ is a colloquial, often affectionate term for a heavy drinker or drunkard, more casual than 飲み手.
Compound of 飲み (nomi, 'drinking', continuative form of 飲む) + 手 (te, 'person'). The meaning 'heavy drinker' is a straightforward extension of 'one who drinks'.