trapdoor Syllabification: (trap·door)Pronunciation: /ˈtrapˌdôr/ (also trap door)Translate trapdoor | into French | into German | into Italian | into Spanish Definition of trapdoor noun a hinged or removable panel in a floor, ceiling, or roof. a feature or defect of a computer system that allows surreptitious unauthorized access to data. trapdoor in other Oxford dictionaries Definition of trapdoor in the British & World English dictionary