backbone

Definition

The series of vertebrae, separated by disks, that encloses and protects the spinal cord, and runs down the middle of the back in vertebrate animals.

Etymology

From Middle English bakbon, bakebon, bac-bon; equivalent to back + bone. Compare the semantically analogous English ridgebone.

Example Sentences

• "Before automobiles, railroads were a backbone of commerce."
• "Undoubtedly it can be said that the humble 0-6-0 has been the backbone for general service, or general utility on British railways right from their earliest days, and is likely to remain so."
• "With little regular employment available in East Kent the backbone of the Kent Coast passenger traffic is therefore the commuters, the not inconsiderable numbers of people who travel each day to their work in Faversham, Sittingbourne, the Medway Towns and most of all, London."