From WordNet (r) 2.0 (August 2003) [wn]:
backbone
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, linchpin,
lynchpin]
2: fortitude and determination; "he didn't have the guts to try
it" [syn: 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,
back, rachis]
4: the part of a network that connects other networks together;
"the backbone is the part of a communication network that
carries the heaviest traffic"
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Backbone \Back"bone"\ (b[a^]k"b[=o]n`), n. [2d back, n. + bone.]
[1913 Webster]
1. The column of bones in the back which sustains and gives
firmness to the frame; the spine; the vertebral or spinal
column.
[1913 Webster]
2. Anything like, or serving the purpose of, a backbone.
[1913 Webster]
The lofty mountains on the north side compose the
granitic axis, or backbone of the country. --Darwin.
[1913 Webster]
We have now come to the backbone of our subject.
--Earle.
[1913 Webster]
3. Firmness; moral principle; steadfastness.
[1913 Webster]
Shelley's thought never had any backbone. --Shairp.
[1913 Webster]
To the backbone, through and through; thoroughly; entirely.
"Staunch to the backbone." --Lord Lytton.
[1913 Webster]
From The Free On-line Dictionary of Computing (19 Sep 2003) [foldoc]:
backbone
<networking> The top level in a hierarchical network. {Stub
networks} and transit networks which connect to the same
backbone are guaranteed to be interconnected.
See also: Internet backbone.
(1998-07-02)