backbone
/ˈbækˌboʊn/ noun B2- 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.
- Any fundamental support, structure, or infrastructure. · Before automobiles, railroads were a backbone of commerce.
- Courage, fortitude, or strength. · He would make a good manager, if he had a little more backbone.
Plural backbones
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