cos ‧ tume /ˈkɒstjʊm $ ˈkɑːstuːm/ BrE AmE noun
[ Date: 1700-1800 ; Language: French ; Origin: Italian , 'custom, dress' , from Latin consuetudo ; ⇨ ↑ custom 1 ]
1 . [countable] a set of clothes worn by an actor or by someone to make them look like something such as an animal, famous person etc ⇨ outfit :
the film’s lavish costumes and spectacular sets
Hallowe'en costumes
2 . [uncountable and countable] clothes that are typical of a particular place or period of time in the past:
The dancers were in national costume.
performers dressed in period costume (=the clothes of a period of history)
3 . [countable] British English a ↑ swimming costume