from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. The spinal column of a vertebrate.
  • n. Zoology Any of various pointed projections, processes, or appendages of animals.
  • n. Botany A strong, sharp-pointed, usually woody outgrowth from a stem or leaf; a thorn.
  • n. Something that resembles or suggests a backbone, as:
  • n. The hinged back of a book.
  • n. The crest of a ridge.
  • n. Strength of character; courage or willpower.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. A person or thing's backbone; the series of bones collectively from one's (literal or figurative) head to tail or pelvis.
  • n. A rigid, pointed surface protuberance or needle-like structure on an animal, shell, or plant.
  • n. Courage or assertiveness.
  • n. The narrow, bound edge of a book.

from the GNU version of the Collaborative International Dictionary of English

  • n. A sharp appendage to any of a plant; a thorn.
  • n.
  • n. A rigid and sharp projection upon any part of an animal.
  • n. One of the rigid and undivided fin rays of a fish.
  • n. The backbone, or spinal column, of an animal; -- so called from the projecting processes upon the vertebræ.
  • n. Anything resembling the spine or backbone; a ridge.

from The Century Dictionary and Cyclopedia

  • n. In botany, a stiff sharp-pointed process, containing more or less woody tissue, and originating in the degeneracy or modification of some organ.
  • n. The backbone; the rachis, spina, or spinal column of a vertebrate.
  • n. A name of some part in various animals.
  • n. In much., any longitudinal ridge; a fin.
  • n. In lace-making, a raised projection from the cordonnet: one of the varieties of pinwork; especially, one of many small points that project outward from the edge of the lace, forming a sort of fringe.
  • n. The duramen or heartwood of trees: a ship-builders' term. See duramen.
  • n. and hemal.
  • n. One of the quills of a harpsichord or spinet.
  • n. Specifically, a sharp, columnar mass of solidified lava which was forced upward to a height of over 1,000 feet above the summit of Mount Pelée, Martinique, in 1903. See volcano, 1. It constituted a new phenomenon in vulcanology. See cut under cumulo-volcano.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • 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
  • n. a small sharp-pointed tip resembling a spike on a stem or leaf
  • n. the series of vertebrae forming the axis of the skeleton and protecting the spinal cord
  • 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
  • n. any sharply pointed projection


Middle English, from Old French espine, from Latin spīna.
(American Heritage® Dictionary of the English Language, Fourth Edition)
From Old French espine (modern French épine) or its source, Latin spīna. (Wiktionary)



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  • In bookbinding, the part of the book visible as the book stands on the shelf in conventional fashion (i.e., not "faced out").

    February 25, 2008