/ Dictionary / Index U underwing: Meaning and Definition of Find definitions for: un•der•wing Pronunciation: (un'dur-wing"), [key] — n. one of the hind wings of an insect. any of several noctuid moths of the genus Catocala, characterized by red-, yellow-, or orange-banded hind wings. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: underwing (Thesaurus) underwhelm underwire Related Content Daily Word Quiz: fabricate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language