Attributive of fancy dress, noun.What are you wearing to the fancy-dress ball?
1934, P. G. Wodehouse, Right Ho, Jeeves:And yet here he was, if one could credit one's senses, about to take part in a fancy-dress ball, a form of entertainment notoriously a testing experience for the toughest. And he was attending that fancy-dress ball, mark you--not, like every other well-bred Englishman, as a Pierrot, but as Mephistopheles--this involving, as I need scarcely stress, not only scarlet tights but a pretty frightful false beard.
