(anatomy, zootomy) A series of bones that support the body and protect the spinal cord, or figuratively, courage or assertiveness.

Something resembling a backbone, such as a ridge, or a long, central structure from which other structures radiate.

The narrow, bound edge of a book that encloses the inner edges of the pages, facing outwards when the book is on a shelf and typically bearing the title and the author's and publisher's name.

(zootomy, botany) A pointed, fairly rigid protuberance or needlelike structure on an animal, shell, or plant.

(botany) The heartwood of trees.

(neuroscience) Ellipsis of dendritic spine..

A linear payscale operated by some large organizations that allows flexibility for local and specific conditions.

(geology) A tall mass of viscous lava extruded from a volcano.

The stiffness of an arrow.