An Etymological Dictionary of the German Language/Annotated/Flügel

by Friedrich Kluge

Flügel, masculine, ‘wing, leaf (of a folding door), aisle, grand piano,’ from the equivalent Middle High German vlügel, masculine.; compare Dutch vleugel, ‘wing’; a late derivative of fliegen. Strange to say, a common Teutonic word is wanting. For an Old Aryan root, ‘to fly,’ see Feder (also Farn).