dress up verb 5dress-up noun 1forms 3 verb5 •To put on special or fancy clothes.Everyone dressed up for the graduation ball.I want a job where I don't have to dress up. •To put on a costume portraying oneself as a particular type of character or well-known person.We're having a party on Saturday, but you must dress up as a famous historical figure. •To put a costume on (someone) portraying them as a particular type of character or well-known person.The cat hated when they dressed him up for Halloween. •To present in a favorable light.You can dress up that proposal however you want; it's still going to go over like a lead balloon. •To decorate; to prettify.Mistress, your father prays you leave your books, And help to dress your sister’s chamber up: You know to-morrow is the wedding-day. — 1590 dress-up noun1 •A child's game of putting on different clothes and pretending to be different people. formsdressed up · dressing up · dresses up