dossière

plural dossières

1. The backplate of a cuirass; an item of plate armor covering the back.

   The body armor consisted of the plastron and dossière (breast and backplates), strapped together at the sides;[…]

   1902, Numismatic and Antiquarian Society of Philadelphia, Proceedings, page 155

   2 more examples

   COMPLETE ARMOR Italian (?) ABOUT 1480 A harness [...] Their character is strongly Italian, and so, too, is the treatment of the dossière, of the knee, and of the shell of the elbow-guard.

   1911, Bashford Dean, Catalogue of a Loan Exhibition of Arms and Armor, New York, N.Y.: Metropolitan Museum of Art, page 7

   It is elaborate armor consisting of large breastplates and dossière connected by leather straps over the shoulders, the two breastplates joined in front under a leather strap which is buckled to a wide leather girdle.

   1924, University of Pennsylvania. University Museum, The Museum Journal, page 178