Casemate
Casemate , noun
[French casemate, from Italian casamatta, prob. from casa house + matto, f. matta, mad, weak, feeble, dim. from the same source as English -mate in checkmate.]
1.
(Fortification) A bombproof chamber, usually of masonry, in which cannon may be placed, to be fired through embrasures; or one capable of being used as a magazine, or for quartering troops.
2.
(Architecture) A hollow molding, chiefly in cornices.