crenellation

from WordNet (r) 3.0 (2006)

crenellation
    n 1: a rampart built around the top of a castle with regular
         gaps for firing arrows or guns [syn: {battlement},
         {crenelation}, {crenellation}]
    2: the action of constructing ramparts with gaps for firing guns
       or arrows [syn: {crenelation}, {crenellation}]

from The Collaborative International Dictionary of English v.0.48

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

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