A kind of shield, or piece of defensive armor, anciently used in war. It was composed of wood, or wickers woven together, covered with skin or leather, fortified with plates of brass or other metal, and worn on the left arm. On the middle was an umbo, boss or prominence, very useful in causing stones and darts to glance off. The buckler often was four feet long, and covered the whole body.

To support; to defend.