Anything broad and limber that hangs loose, or that is attached by one side or end and is easily moved; as, the flap of a garment. A cartilaginous flap upon the opening of the larynx. (Sir t. Browne)
2. A hinged leaf, as of a table or shutter.
3. The motion of anything broad and loose, or a stroke or sound made with it; as, the flap of a sail or of a wing.
4. (Science: veterinary) a disease in the lips of horses. Flap tile, a tile with a bent up portion, to turn a corner or catch a drip.
(Science: mechanics) flap valve, a valve which opens and shuts upon one hinged side; a clack valve.
Origin: oe. Flappe, flap, blow, bly-flap; cf. D. Flap, and E. Flap.