backbone Meaning, Definition & Usage

noun a central cohesive source of support and stability
mainstay; linchpin; lynchpin; keystone; anchor.
- faith is his anchor
- the keystone of campaign reform was the ban on soft money
- he is the linchpin of this firm
noun fortitude and determination
grit; gumption; guts; sand; moxie.
- he didn't have the guts to try it
noun the series of vertebrae forming the axis of the skeleton and protecting the spinal cord
rachis; spinal column; spine; vertebral column; back.
- the fall broke his back
noun 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
spine.
- the title and author were printed on the spine of the book
noun the part of a network that connects other networks together
- the backbone is the part of a communication network that carries the heaviest traffic

2d back,n.+ bone.

The column of bones in the back which sustains and gives firmness to the frame; the spine; the vertebral or spinal column.
Anything like , or serving the purpose of, a backbone.
The lofty mountains on the north side compose the granitic axis, or backbone of the country. Darwin.

We have now come to the backbone of our subject. Earle.
Firmness; moral principle; steadfastness.
Shelley's thought never had any backbone. Shairp.