1. the underside of a bird’s or insect’s wing
2. a type of moth with colorful hind wings that are normally hidden
Usage: entomology

Examples

• The bird spread its wings, revealing the bright red markings on its underwing.
• Scientists study the underwing patterns to identify different bird species.
• The underwing moth gets its name from its vibrant hind wings.
• When the moth is at rest, its colorful underwing is completely concealed.
• The field guide shows detailed illustrations of each species’ underwing coloration.
• Birdwatchers often use underwing markings as key identification features.