Origin: Latin suffix -tion
Crenellation has 3 different meanings across 1 category:
a rampart built around the top of a castle with regular gaps for firing arrows or guns
the action of constructing ramparts with gaps for firing guns or arrows
A pattern along the top of a parapet (fortified wall), most often in the form of multiple, regular, rectangular spaces in the top of the wall, through which arrows or other weaponry may be shot, especially as used in medieval European architecture.