Carcasses are commodities which can be made from corpses using the 'carve' command. The number of carcasses you can get from a single corpse depend on how large the creature who died was.

Carcasses can be processed at Butchers industries into meat, oil and bone, which can then be used to make other items, such as food.

If you are desperate for food and don't have access to a butchers, you can 'roast carcasses' at a campfire, though take care as badly cooked meat can make you ill.