Definition of flap

• v. - 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.
• v. - A hinged leaf, as of a table or shutter.
• v. - 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.
• v. - A disease in the lips of horses.
• n. - To beat with a flap; to strike.
• n. - To move, as something broad and flaplike; as, to flap the wings; to let fall, as the brim of a hat.
• v. i. - To move as do wings, or as something broad or loose; to fly with wings beating the air.
• v. i. - To fall and hang like a flap, as the brim of a hat, or other broad thing.