trapdoor

noun

A hinged or sliding door set into a floor or ceiling. / (theater) Such a trap set into the floor of a stage to allow fast exits and entrances.

The trapdoor creaked open, revealing a hidden passage.

意味（1）

A hinged or sliding door set into a floor or ceiling.

意味（2）

(theater) Such a trap set into the floor of a stage to allow fast exits and entrances.

意味（3）

(computing) A secret method of obtaining access to a program or online system; a backdoor.

意味（4）

(mathematics, cryptography) The special information that permits the inverse of a trapdoor function to be easily computed.

意味（5）

(mining) A door in a level for regulating the ventilating current; a weather door.