From Longman Dictionary of Contemporary Englishmixed doublesˌmixed ˈdoubles noun [uncountable] DSa game in a sport such as tennis in which a man and a woman play against another man and woman
Examples from the Corpus
mixed doubles• Among the guests, with girl-friend Babs Feltus, was some one who also knows about mixed doubles - Boris Becker.• There were four competitions: men's singles, women's singles, women's doubles and mixed doubles.• Because I must have been noticed, I was invited by the families to play in mixed doubles.• On Sunday play starts with the mixed doubles at 9am with the men's open singles starting at 10am. 