What is firmness; moral principle; steadfastness. Shelley's thought never had any backbone. Shairp. To the backbone, through and through; thoroughly; entirely. "Staunch to the backbone." Lord Lytton called?

backbone — Firmness; moral principle; steadfastness. Shelley's thought never had any backbone. Shairp. To the backbone, through and through; thoroughly; entirely. "Staunch to the backbone." Lord Lytton. (Webster's 1913.)