plaquet

plural plaquets

1. archaicSynonym of placard, a metal plate reinforcing the lower part of an armor breastplate or backplate.

   […] The plate of steel used as additional defence, and specifically the doubling of the lower part of the breastplate; a similar plaquet was used for the back.

   1899, Leicester (England), Records of the Borough of Leicester: 1103-1327, page 340

   1 more example

   To the back-piece of the cuirass for the protection of the loins, was hooked on a piece of armour, called Garde des Reins, or culettes; and the breast-piece was occasionally strengthened by an additional plate called a Plaquet.

   1786, Francis Grose, A Treatise on Ancient Armour and Weapons, page 21

   Synonyms: placard