trapdoor spider

Webster's Dictionary (GCIDE)

1.(Arch.) A lifting or sliding door covering an opening in a roof or floor. [1913 Webster]

2.(Mining) A door in a level for regulating the ventilating current; -- called also weather door. --Raymond. [1913 Webster]

Trapdoor spider (Zool.), 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). [1913 Webster]