embrasure

城垛城齿间的凹口；城墙或胸墙上可发射武器的开口。

Any of the indentations between the merlons of a battlement; an opening in a wall or parapet through which ordnance can be fired.

用于射击的开口(在墙壁、船或装甲车辆上)

an opening (in a wall or ship or armored vehicle) for firing through

任何小的防护空间。

Any small protected space.

墙上用于门或窗的斜面凹口,内大外小。

The slanting indentation in a wall for a door or window, such that the space is larger on the inside than the outside.