Underwings

Part of speech: noun

Definitions

1. The pairs of secondary wings situated beneath the primary wings of certain insects, which are usually concealed when the insect is at rest
2. The underside surfaces of wings in aviation design that play a role in lift and aerodynamics
3. The secondary wings located beneath the main wings that are typically folded away in insects ; the bottom side of airplane wings important for generating lift and controlling aerodynamics

Etymology: "Underwings" is simply the plural of "underwing," a compound formed from "under" and "wing." Both parts are very old English words: "under" descends from Old English "under," ultimately from the Proto-Germanic "under," and "wing" comes from Middle English "winge," which took its place in the language from Old Norse "vængr." The compound itself is transparent: an underwing is the wing that lies beneath another. The second element is where the word's history is most telling. Long before "wing" meant anything in aviation, it described the flight organ of birds and insects, and "underwing" was used of those creatures' hidden hind wings, which folded beneath the front pair. The same logic carried over to aircraft, where the underside of a wing is the surface that matters most for lift and control.

Synonyms: wing undersides