■ noun
1》 a series of vertebrae extending from the skull to the small of the back, enclosing the spinal cord and providing support for the thorax and abdomen; the backbone.
2》 a central feature or main source of strength.
3》 the part of a book's jacket or cover that encloses the inner edges of the pages.
4》 chiefly Zoology & Botany a prickle or other hard pointed projection or structure.
5》 (also pay ~ ) a linear pay scale operated by some large organizations that allows flexibility for local and specific conditions.
Derivatives
-~d adjective
Origin
ME: shortening of OFr. e~ , or from L. spina 'thorn, backbone'.