Buckler

n. [Fr. bouclier, Pr. bloquier, It. brocchier, O. H. Ger. buckeler, a shield with a boss or prominence, from O. Fr. bocle, boucle, Pr. bocla, Lat. buccula. See BUCKLE.]

1Sense 1. A kind of shield, or piece of defensive armor, anciently used in war. It was often four feet long, and covered the whole body.

Pillowed on buckler cold and hard. W. Scott.

2Sense 2. (Paleon.) The anterior segment of the carapax or shell in trilobites. Dana.

3Sense 3. (Naut.) A block of wood made to fit in the hawse-holes, to prevent a vessel from taking in water in pitching. Totten.