(informal) One who dampens fun; especially, one who declines to participate in or enjoy a party or some other group activity; one who does not agree with the opinions of a group.

plural of war party

A group of people assembled to carry out a military attack.

plural of boarding party

Politics that is dominated by rivalry between political parties

A sleepover; a party where people stay and sleep overnight.

(US, idiomatic, dated) An execution by hanging, especially a lynching.

plural of tailgate party

A celebration, held in a parking lot, with picnic food served out of the back of automobiles or pickup trucks.

Of or relating to a third party.