flap [flapped, flapping, flaps](to move (something broad and loose) up and down) verb [UK: flæp] [US: ˈflæp]The bird flapped its wings. = Fågeln flaxade med sina vingar.
flutter [fluttered, fluttering, flutters](to flap the wings without flying) verb [UK: ˈflʌ.tə(r)] [US: ˈflʌ.tər]