A party where the only clothing worn is pants (i.e. a shirtless gathering). / (by extension) A clothing-optional party, where the intent is to engage in sexual activity.

(Singapore) A party for expatriates at which all the guests wear sarongs.

plural of party foul

(colloquial) A faux pas committed at a party.

(idiomatic) the party where teenagers or young adults bring with them a lot of random pills, take them, and see what happens

plural of skittles party

A group of entertainers, or Pierrots, popular in Britain during the first half of the 20th century / a group of people acting in concert in a takeover bid

garden party

A party held to celebrate a person's birthday.

plural of birthday party