Also found in: Thesaurus.
v. (ŭn′dər-drĕs′) un·der·dressed, un·der·dress·ing, un·der·dress·es
1. To dress oneself too informally for an occasion: Don't underdress for the wedding; blue jeans are not appropriate attire.
2. To dress oneself too lightly: When it began to snow, I realized I had underdressed for the hike.
1. To dress too informally for an occasion: Seeing the other guests in their evening gowns made me feel I had underdressed myself.
2. To dress too lightly: You're underdressing the baby for such a cold day!
1. Apparel worn beneath outer garments; underclothing.
2. An outer garment, such as a dress beneath a tunic or coat, that is worn as part of a costume or suit.
(Clothing & Fashion) wearing clothes that are not elaborate or formal enough for a particular occasion