From Longman Dictionary of Contemporary Englishtrapdoortrap‧door /ˈtræpdɔː $ -dɔːr/ noun [countable] TBBa small door that covers an opening in a roof or floor
Examples from the Corpus
trapdoor• Internal access to this lower room was obtained through a trapdoor in the floor of the drop room.• They might ambush you when you stuck your head up a trapdoor and stab you with a pike.• He was certain he had found a cleverly concealed trapdoor.• They went from door to door, questioning everyone, systematically searching for trapdoors.• They were careful with each other; they did not talk about the sadness or the sudden trapdoor feeling in their stomachs.• The trapdoor above 1c is closed but unlocked.• At the top of the spiral staircases are two wooden trapdoors leading on to the battlements. 