A trapdoor is a door set into a floor or ceiling (depending on what side of the door one is on). An exposed trapdoor could also be called a hatch, although hatches may not be necessarily horizontal. Many buildings with flat roofs have hatches that provide access to the roof; on ships, hatches provide access to the deck. A small door in a wall, floor or ceiling used to gain access to equipment is called an access hatch. Hidden trapdoors occasionally appear in fiction, either as entrances to secret passageways, or as literal traps into which a hapless pedestrian may fall if he or she happens to stand on one.

Most 19th and 20th century gallows featured a trapdoor, usually with two flaps. The victim was placed at the join.The edge of a trapdoor farthest from the hinge accelerates faster than gravity, so that the victim does not hit the flaps but falls freely

The word "trapdoor" or simply "trappies" can be used as an expression of dismay or defeat, in an acknowledgment that something has not gone to plan, or that someone has committed a schoolboy error of some kind, eg. leaving English to go and play mini-soccer. It is generally accompanied by a hand gesture and an exclamation of "trappies" in a sneering and obnoxious surf-voice.

See also

• Trap