• (n.) Armor for the arm; -- generally used for the whole arm from the shoulder to the wrist, and consisting, in the 15th and 16th centuries, of many parts.
Bras'sart noun [ French brassard , from bras arm. See Brace , noun ] Armor for the arm; -- generally used for the whole arm from the shoulder to the wrist, and consisting, in the 15th and 16th centuries, of many parts. 
Brassarts were pieces of ancient plate armour which united the armour-plates on the shoulder and the elbow.