costume -- (the attire worn in a play or at a fancy dress ball; "he won the prize for best costume")
costume -- (unusual or period attire not characteristic of or appropriate to the time and place; "in spite of the heat he insisted on his woolen costume")
costume -- (the prevalent fashion of dress (including accessories and hair style as well as garments))
costume -- (the attire characteristic of a country or a time or a social class; "he wore his national costume")
Overview of verb costume
The verb costume has 2 senses
costume, dress up -- (dress in a costume; "We dressed up for Halloween as pumpkins")
costume -- (furnish with costumes; as for a film or play)