From Longman Dictionary of Contemporary Englishparty pieceˈparty ˌpiece noun [countable] British English DLa song, dance etc that you often perform to entertain people at parties
Examples from the Corpus
party piece• Then came Solano's party piece, and a frantic finish.• Together they revived their party piece from the Sixties, Open Country, which like everything they played, was superb. 