noun the series of vertebrae forming the axis of the skeleton and protecting the spinal cord.
— synonyms: spinal_column, vertebral_column, backbone, back, rachis
noun any sharply pointed projection.
— synonyms: spur, acantha
noun a small sharp-pointed tip resembling a spike on a stem or leaf.
— synonyms: thorn, prickle, pricker, sticker, spikelet
noun the part of a book's cover that encloses the inner side of the book's pages and that faces outward when the book is shelved.
— synonyms: backbone