Is it farther or further?
late 13c., from Anglo-French carcois, from or influenced by Old French charcois (Modern French carcasse) "trunk of a body, chest, carcass," and Anglo-Latin carcosium "dead body," all of uncertain origin. Not used of humans after c.1750, except contemptuously. Italian carcassa probably is a French loan word.
A human body; one's body, esp if heavy: set his carcass on the couch