Backbone - Definition

n 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" [syn:
anchor, mainstay, keystone, backbone, linchpin,
lynchpin]
2: fortitude and determination; "he didn't have the guts to try
it" [syn: backbone, grit, guts, moxie, sand,
gumption]
3: the series of vertebrae forming the axis of the skeleton and
protecting the spinal cord; "the fall broke his back" [syn:
spinal column, vertebral column, spine, backbone,
back, rachis]
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" [syn: spine, backbone]
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"