0 a party where people wear special clothes that make them look like a particular character, animal or object:
Before this race, a costume party is usually held, and participants swim in this river with their costume on.
The girls are invited to the costume party.
Different types of party such as children's party, cocktail party, garden party and costume party would tend to require different styles of dress.
That night, the gang attends a costume party dinner.
The two met at a costume party and signed a record deal a year later.
At the end of term, a traditional costume party is held.
Favoring him, the outcasts don't want him a part of their upcoming costume party plot.
Ballard himself makes a cameo appearance at the costume party scene.