noun
trick sake cup that cannot be set down until empty
A traditional drinking vessel designed with a hole or shape that forces the drinker to finish the sake before putting the cup down. Often used at parties or ceremonies.
宴会で可杯が出されて、みんな一気に飲み干した。
At the party, trick sake cups were brought out and everyone downed their drinks in one go.
The name 可杯 (べくはい) likely derives from the shape or mechanism that makes it impossible to set down, but the exact origin is uncertain.