A body was the physical structure of an animal or a sentient individual.
In 2265, the bodies of USS Enterprise crewmembers who were affected by the galactic barrier were autopsied. In each case, it was discovered that there was damage to the body's neural circuit, with an area of the brain burned out. (TOS: "Where No Man Has Gone Before")
After the Enterprise time traveled from 2268 to 1968 and intercepted the transporter beam of Gary Seven, Doctor Leonard McCoy performed a medical analysis of Seven which determined he had a totally perfect body without a single physical flaw. (TOS: "Assignment: Earth")
In 2365, when Commander William T. Riker expressed that Salia seemed too delicate for the task of reuniting a warring planet, Lieutenant Worf advised him not to be fooled by looks, that the body is just a shell. (TNG: "The Dauphin")