spine

Noun

• a sharp rigid animal process or appendage; as a porcupine quill or a ridge on a bone or a ray of a fish fin

• 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
  • the title and author were printed on the spine of the book
    

• a small sharp-pointed tip resembling a spike on a stem or leaf

• any sharply pointed projection

• the series of vertebrae forming the axis of the skeleton and protecting the spinal cord
  • the fall broke his back
    

Related words

• Synonyms: 
  backbone , thorn , prickle , pricker , sticker , spikelet , spur , acantha , spinal column , vertebral column , back , rachis