The term 'of the backbone' can be summed up by the word 'SPINAL, ' which is a six-letter word. The spine, or backbone, is a column of bones that runs from the base of the skull to the pelvis. It is made up of 33 vertebrae, which are separated by discs and connected by ligaments and muscles. The spine provides support for the body and allows us to move in different directions. It also protects the SPINAL cord, which is a bundle of nerves that carries signals between the brain and the rest of the body.