Embrasure

n.	1.	An embrace.
	1.	(Arch.) A splay of a door or window. Apart, in the twilight gloom of a window's embrasure, Sat the lovers. - Longfellow.
	2.	(Fort.) An aperture with slant sides in a wall or parapet, through which cannon are pointed and discharged; a crenelle. See Illust. of Casemate.

Noun

1.

embrasure - an opening (in a wall or ship or armored vehicle) for firing through Synonyms: porthole, port

opening, port, porthole, ship