'Crenelation' definitions:

Definition of 'crenelation'

(from WordNet)
noun
A rampart built around the top of a castle with regular gaps for firing arrows or guns [syn: battlement, crenelation, crenellation]
noun
The action of constructing ramparts with gaps for firing guns or arrows [syn: crenelation, crenellation]

Definition of 'Crenelation'

From: GCIDE
  • 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.] [1913 Webster] Crenelle