The term 'backbone-related' can be summarized by the crossword solution 'SPINAL, ' which is a six-letter word. The spine, or SPINAL column, is a major component of the human body's skeletal system. It is made up of 33 vertebrae and is responsible for providing support and protection to the central nervous system. The spine also helps to maintain posture and balance, and it is connected to the ribcage, which provides additional support. In addition, the spine is essential for movement, as it allows us to bend and twist our bodies.