trapdoor

[trap-dawr, -dohr] /ˈtræpˈdɔr, -ˈdoʊr/
noun
1.
a door flush with the surface of a floor, ceiling, or roof.
2.
the opening that it covers.
adjective
3.
of, pertaining to, or like a trapdoor.
Also, trap door.
Origin
1325-75; Middle English trappe dore. See trap1, door