party pooper

[ poo-per ]
/ ˈpu pər /

noun Slang.

a person who hasn't the interest or vitality to participate actively in a social party and whose mood, attitude, or personality lessens others' enjoyment; killjoy.
Also called poop.

Origin of party pooper

First recorded in 1940–45; poop2 + -er1

British Dictionary definitions for party pooper

party pooper
/ (ˈpuːpə) /

noun

informal a person whose behaviour or personality spoils other people's enjoyment

Word Origin for party pooper

C20: originally US