underwing — English Dictionary

Noun

1. A hind wing on an insect.

   Examples

   The upper wings of the moth which Jacob held were undoubtedly marked with kidney-shaped spots of a fulvous hue. But there was no crescent upon the underwing.

2. A member of the genus Catocala, a nocturnal moth which usually has brightly coloured underwings.

3. The underside of a bird's wing.

   Examples

   More examples (1)

   The ‘white-tailed’ kites in the genus Elanus (‘kite’) are small, gull-like, grey-and-white hawks with black forewing patches and varying amounts of black on the underwings.

Noun

1. moth having dull forewings and brightly colored hind wings

   Broader terms

   noctuid mothnoctuidowlet moth