the hind wing of an insect, esp when covered by the forewing - See red underwing, yellow underwing
WordReference Random House Unabridged Dictionary of American English © 2026
un•der•wing
(un′dər wing′),USA pronunciation n.
- Insectsone of the hind wings of an insect.
- Insectsany of several noctuid moths of the genus Catocala, characterized by red-, yellow-, or orange-banded hind wings.
- under- + wing 1525–35
Collins Concise English Dictionary © HarperCollins Publishers::
'underwing' also found in these entries (note: many are not synonyms or translations):