Spine (?), n. [L. spina thorn, the spine; akin to spica a point: cf. OF. espine, F. 'epine. Cf. Spike, Spinet a musical instrument, Spinny.] 1. Bot. A sharp appendage to any of a plant; a thorn.
2. Zool. (a) A rigid and sharp projection upon any part of an animal. (b) One of the rigid and undivided fin rays of a fish.
3. Anat. The backbone, or spinal column, of an animal; -- so called from the projecting processes upon the vertebrae.
4. Anything resembling the spine or backbone; a ridge.
© Webster 1913. | 
