名詞 embrasure:

1. an opening (in a wall or ship or armored vehicle) for firing through
   同義詞：port, porthole

em.bra.sure

n.（名詞）
An opening in a thick wall for a door or window, especially one with sides angled so that the opening is larger on the inside of the wall than on the outside.
斜面洞：在門或窗的厚壁上開的一個洞，尤指有斜面角的，這樣里面開的比外面開的大
A flared opening for a gun in a wall or parapet.
槍眼，炮眼：在墻或護墻上開的用于射擊的洞口

來源：
French
法語
from embraser [to widen an opening]
源自 embraser [擴大開口]

【引伸】
embra.sured
adj.（形容詞）