It comes from the Latin word "caro," meaning flesh. You can see this in words like:
* Carnivore: An animal that eats flesh.
* Carnation: A flower that was once thought to be a cure for carbuncles (flesh infections).
* Carnificina: A massacre or slaughter.
However, "carno" can also be found in some scientific terms, such as "carnosine," an amino acid found in muscle tissue, where it has a different meaning related to the specific compound.