Definitions

1. noun

The wing of an airplane or other aircraft that is underneath the fuselage, especially one that is used to lift the aircraft during landing.

“The underwing of the plane made it harder to maneuver during the storm.”

2. noun

In a butterfly, the part of the hindwing that is underneath and usually more colorful than the dorsal surface.

“The vibrant colors on the underwing of the monarch butterfly were breathtaking.”

3. verb

To support or provide a foundation for (something)

“The underwing of the project was a well-structured plan.”