n. 1. One who, or that which, flaps. [ 1913 Webster ]

2. See Flipper. “The flapper of a porpoise.” Buckley. [ 1913 Webster ]

3. A flat object used to make a flapping noise by striking another object. RHUD [ PJC ]

4. A flat and broad object hanging from a larger object, either flexible like rubber or hinged to allow a swinging motion; a flap.

5. A young woman who dresses in a modern, stylish manner and behaves unconventionally in social situations; -- a term used especially to refer to young women during the 1920's and their peculiar style of dress. [ PJC ]

Flapper skate (Zool.), a European skate (Raia intermedia). [ 1913 Webster ]