costume party

1. N-COUNT A costume party or costume ball is a party at which the guests try to look like famous people or people from history, from stories, or from particular professions. 化裝舞會[美國英語]

...a pair of angels' wings and a halo that she'd worn to a costume party just a few months before. ...僅僅幾個月前她穿到化裝舞會上去的一對天使翅膀和光環(huán)。