costume
noun
a style of dress, including accessories and hairdos, especially that peculiar to a nation, region, group, or historical period.
Used to describe an ongoing action or continuous state that was happening at a specific time in the past.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
"What part am I to spoil?" he asked, as he entered the green room, where several excited young gentlemen were costuming and attitudinizing.
From Behind a Mask, or a Woman's Power by Louisa May Alcott