The backbone is an articulate structure.
He has no backbone.
These men are the backbone of the country.
a central cohesive source of support and stability
同义词：anchor, mainstay, keystone, linchpin, lynchpin
fortitude and determination
同义词：grit, guts, moxie, sand, gumption
the series of vertebrae forming the axis of the skeleton and protecting the spinal cord
同义词：spinal column, vertebral column, spine, back, rachis
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 part of a network that connects other networks together