Trapdoor
Trapdoor , noun
1.
(Architecture) A lifting or sliding door covering an opening in a roof or floor.
2.
(Mining) A door in a level for regulating the ventilating current; -- called also weather door. — Raymond
Collocations (1)
Trapdoor spider (Zoology) , any one of several species of large spiders which make a nest consisting of a vertical hole in the earth, lined with a hinged lid, like a trapdoor. Most of the species belong to the genus Cteniza, as the California species (Cteniza Californica).