A piece of material that is attached on one side and can be moved freely, often used to cover an opening. The envelope had a flap that needed to be sealed before mailing.
A state of agitation or panic. There was a flap in the office when the fire alarm went off unexpectedly.
A rapid movement up and down, typically referring to wings or arms. The bird took off with a flap of its wings.
A part of an aircraft wing that can be moved to control lift and drag. The pilot adjusted the flaps to prepare for landing.
A piece of living tissue partly detached and used for grafting or reconstructive surgery while still attached to its original blood supply. The surgeon rotated a skin flap to cover the burn area.