A cuirass is a piece of armor that covers the back and chest. It was worn during medieval times as part of a full suit of body armor or on its own.
Cuirass came to English via the French word cuirasse, which itself originated from the Latin word corium, meaning leather. Cuirasses were originally made from leather, but were later constructed from metal or another rigid material. A metal cuirass could be very heavy, so it was sized to fit so that its weight would rest on the wearer's hips and not hang from his shoulders. Although they existed earlier, cuirasses were particularly popular during the Middle Ages.