trap door(n = noun.artifact) - a hinged or sliding door in a floor or ceiling;
is a kind of door
accordion door, back door, barn door, bi-fold door, booby trap, car door, cargo door, door, door guard, door latch, door prize, double door, dutch door, exterior door, fire door, folding door, french door, front door, half door, hatchback door, interior door, iron trap, lobster trap, louvered door, mouse trap, next door, open door, outside door, poverty trap, revolving door, sand trap, screen door, service door, show the door, side door, sliding door, solar trap, speed trap, stage door, steel trap, storm door, swing door, swinging door, trap, trap block, trap line, trap play, trap shooting, wicket door