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.