Anti-bodies are proteins produced by the immune system to fight off foreign invaders such as bacteria and viruses. They are also known as immunoglobulins, and they recognize and bind to specific antigens on the surface of the invader. The term 'anti-bodies' is derived from the fact that they act as the body's defense against these foreign substances. The crossword solution for the term 'anti-bodies' is 'FOES, ' which is an appropriate description of how anti-bodies work to protect the body from harm.