to dress more plainly or informally than is indicated by the occasion
- Apparel worn beneath outer garments; underclothing.
- An outer garment, such as a dress beneath a tunic or coat, that is worn as part of a costume or suit.
verbun·der·dressed, un·der·dress·ing, un·der·dress·es
To dress too informally for an occasion: Remember not to underdress for the wedding.
To dress (oneself, for example) too informally for an occasion: You don't want to be underdressed at the awards ceremony.
(third-person singular simple present underdresses, present participle underdressing, simple past and past participle underdressed)
From under- +"Ž dress.