The Collaborative International Dictionary
Backpiece \Back"piece`\, Backplate \Back"plate`\, n. [Back, n. or a. + piece, plate. ]
A piece, or plate which forms the back of anything, or which covers the back.
Specifically: A piece of plate armor protecting the back; -- it is worn as part of a cuirass.
Wiktionary
n. 1 A decorated comb that attaches a veil to the back of a bride's head. 2 A large tattoo on a person's back.
Usage examples of "backpiece".
Harper took off the backpiece and filed the grip, and then he varnished it with oil and beeswax until the handle was dark brown and shining.
Saryn, looking up from where she smoothed a curved backpiece for what looked to be a chair.
Seeing this, the good man, as carefully as he could, removed the breastplate and backpiece to see if he was wounded but did not see blood or cuts of any kind.
They were almost ready for the performance, everything in place except the final blessings of the chamberlains and their magists, and Eslingen paused at the center of the backpiece, peering out through the single narrow slit in the stiff canvas.