Source : Webster's Revised Unabridged Dictionary (1913)

Poitrel \Poi"trel\, n. [OE. poitrel, F. poitrail, fr. L.
   pectorale a breastplate, fr. pectoralis, a. See {Pectoral},
   a.] (Anc. Armor)
   The breastplate of the armor of a horse. See {Peytrel}.
   [Obs.] --Chaucer.