枪眼设备
Crenelation \Cren`el*a"tion\ (-?"sh?n), n. The act of crenelating, or the state of being crenelated; an indentation or an embrasure. [Written also {crenellation}.]
crenellation n 1: a rampart built around the top of a castle with regular gaps for firing arrows or guns [syn: {battlement}, {crenelation}] 2: the action of constructing rampparts with gaps for firing guns or arrows [syn: {crenelation}]