The Collaborative International Dictionary of English v.0.48:

Kiva \Ki"va\, n. [Hopi name, sacred chamber.]
   A large chamber built under, or in, the houses of a Pueblo
   village, used as an assembly room in religious rites or as a
   men's dormitory. It is commonly lighted and entered from an
   opening in the roof.
   [Webster 1913 Suppl.]