backbone meaning and definition

BACKBONE noun

Definition of backbone (noun)

1. a central cohesive source of support and stability
   • "faith is his anchor"; "the keystone of campaign reform was the ban on soft money"; "he is the linchpin of this firm"
   • synonyms: anchor, keystone, linchpin, lynchpin, mainstay
2. fortitude and determination
   • "he didn't have the guts to try it"
   • synonyms: grit, gumption, guts, moxie, sand
3. the series of vertebrae forming the axis of the skeleton and protecting the spinal cord
   • "the fall broke his back"
   • synonyms: back, rachis, spinal column, spine, vertebral column
4. the part of a book's cover that encloses the inner side of the book's pages and that faces outward when the book is shelved
   • "the title and author were printed on the spine of the book"
   • synonyms: spine
5. the part of a network that connects other networks together
   • "the backbone is the part of a communication network that carries the heaviest traffic"