expression
drink like a fish; ready to drink sake by the keg
Idiomatic expression describing someone who can drink a huge amount of alcohol without hesitation. Often used in a lighthearted or admiring way.
彼は斗酒なお辞せずという感じで、次々とビールを空けていった。
He was drinking like a fish, emptying one beer after another.
The expression originates from classical Chinese literature, where 斗 (a unit of volume) and 酒 (sake/alcohol) combine with なお辞せず (not declining even so) to mean 'not refusing even a large amount of sake.'