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Meaning of underwing

un•der•wing

Pronunciation: (un'dur-wing"), [key]
— n.
  1. one of the hind wings of an insect.
  2. 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.
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