breastplate Meaning, Definition & Usage

  1. noun armor plate that protects the chest; the front part of a cuirass
    egis; aegis.

WordNet

Breast"plate` noun
Definitions
  1. A plate of metal covering the breast as defensive armor.
    Before his old rusty breastplate could be scoured, and his cracked headpiece mended. Swift.
  2. A piece against which the workman presses his breast in operating a breast drill, or other similar tool.
  3. A strap that runs across a horse's breast. Ash.
  4. (Jewish Antiq.) A part of the vestment of the high priest, worn upon the front of the ephod. It was a double piece of richly embroidered stuff, a span square, set with twelve precious stones, on which were engraved the names of the twelve tribes of Israel. See Ephod.

Webster 1913