battlement
noun
[ ˈbat(ə)lm(ə)nt ]
• a parapet at the top of a wall, especially of a fort or castle, that has regularly spaced squared openings for shooting through.
Similar:
castellation,
parapet,
rampart,
balustrade,
wall,
bulwark,
barbican,
bastion,
fortification,
breastwork,
crenellation,
circumvallation,
outwork,
vallum,
bartizan,
Origin:
late Middle English: from Old French bataillier ‘fortify with movable defence turrets’, possibly related to battle.