Breastplate
BREAST'PLATE, noun [breast and plate.]
1. Armor for the breast.
2. A strap that runs across a horse's breast.
3. In Jewish antiquity, a part of the vestment of the high priest, consisting of a folded piece of the rich embroidered stuff of which the ephod was made. It was set with twelve precious stones, on which were engraved the names of the twelve tribes.