Ăb'a-tĭs or Ăb'at-tĭs, n.

noun

(Synop., § 130), n. [Fr. abatis, abattis, from abattre. See ABATE.] (Fort.) A row of the large branches of trees, sharpened and laid with the points outward, in front of a fortification or any other position, to obstruct the approach of assailants. The larger ends of the branches are secured to the ground by forked pickets.

A labeled cross-section diagram of fortifications, showing an abatis, banquette, fraise, palisade, parapet, scarp, and counterscarp. — a, a, abatis; b, b, banquette; f, g, fraise; p, p, palisade; c, c, breast-height, or interior slope; c, d, interior crest; d, g, g, c, parapet; g, h, scarp; q, q, counterscarp.