A party pooper is a person who ruins the mood of a celebration. Do not be a party pooper.
It is informal and mildly rude, and it is aimed at somebody who objects rather than somebody who is quiet. Being the party pooper is sometimes exactly the right thing to be.
1nounparty pooperA person who ruins the mood of a celebration.
“Somebody had to be the party pooper and mention the neighbours.”
party pooper is a person.
Practised in Idioms