From HomoExcelsior

1. The spinal column of a vertebrate. 2. Any of various pointed projections, processes, or appendages of animals. 3. A strong, sharp-pointed, usually woody outgrowth from a stem or leaf; a thorn. 4. Something that resembles or suggests a backbone, as: 5. The hinged back of a book. 6. The crest of a ridge. 7. Strength of character; courage or willpower.

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