noun
drunkard; reveller
A person who is very drunk, often to the point of losing control. The term is somewhat formal or literary; in everyday speech, 酔っ払い is more common.
深夜の駅には酩酊者が何人も倒れていた。
Late at night, several drunkards were lying collapsed at the station.
彼は酒に弱いくせに、いつも酩酊者になってしまう。
Even though he can't hold his liquor, he always ends up a drunkard.
酩酊 is the state of being very drunk; 酩酊者 is the person in that state.
From 酩酊 (meitei, 'heavy drunkenness') + 者 (sha, 'person'). The word 酩酊 is of Chinese origin, combining 酩 (drunk) and 酊 (intoxicated).