-backbone-

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 ]