1. medieval body armor that covers the chest and back
The Collaborative International Dictionary of English v.0.48:
Cuirass \Cui*rass"\ (kw[-e]*r[.a]s", or kw[=e]"r[a^]s; 277), n.;
pl. Cuirasses(-[e^]z). [F.cuirasse, orig., a breastplate of
leather, for OF. cuir['e]e, cuirie influenced by It. corazza,
or Sp. coraza, fr. an assumed LL. coriacea, fr. L. coriaceus,
adj., of leather, fr. corium leather, hide; akin to Gr.
cho`rion intestinal membrane, OSlav. skora hide, Lith. skura
hide, leather. Cf. Coriaceous.]
(a) A piece of defensive armor, covering the body from the
neck to the girdle.
(b) The breastplate taken by itself.
Note: The cuirass covered the body before and behind. It
consisted of two parts, a breast- and backpiece of iron
fastened together by means of straps and buckles or
other like contrivances. It was originally, as the name
imports, made of leather, but afterward of metal.
2. (Zool) An armor of bony plates, somewhat resembling a
WordNet (r) 3.0 (2006):
n 1: medieval body armor that covers the chest and back