flap

noun

anything flat and broad that is attached at one end and hangs loose or covers an opening: the flap of a pocket
the motion or slapping sound of a swinging flap: the flap of an awning
Archaic a blow with something broad and flat; slap
either of the two parts of a book's dust jacket that fold inside the book's covers and that usually contain a summary of the book's contents and a brief biographical sketch of its author
Informal a state of excitement, controversy, or agitation
Aeron. a pilot-controlled airfoil; esp., a section hinged to the trailing edge of a wing between the aileron and the fuselage, usually used to increase lift or drag
Phonet. a sound articulated with a single rapid touch of the tongue against the roof of the mouth
Surgery a piece of tissue partly detached from the surrounding tissue, as for grafting

transitive verb flapped, flapping

to strike with something flat and broad; slap
to move back and forth or up and down as in beating the air, usually with some noise: a bird flapping its wings
to throw, fling, slam, etc. abruptly or noisily

intransitive verb