Source : Webster's Revised Unabridged Dictionary (1913)

Battlement \Bat"tle*ment\ (-ment), n. [OE. batelment; cf. OF.
   bataillement combat, fr. batailler, also OF. bastillier,
   bateillier, to fortify. Cf. {Battle}, n., {Bastile},
   {Bastion}.] (Arch.)
      (a) One of the solid upright parts of a parapet in ancient
          fortifications.
      (b) pl. The whole parapet, consisting of alternate solids
          and open spaces. At first purely a military feature,
          afterwards copied on a smaller scale with decorative
          features, as for churches.

Source : WordNet®

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