spine Meaning and Definition

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

2. n. 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

3. n. the series of vertebrae forming the axis of the skeleton and protecting the spinal cord

4. n. a small sharp-pointed tip resembling a spike on a stem or leaf

5. n. any sharply pointed projection