rachis

  1. Noun.  (botany) The main shaft of either a compound leaf, head of grain, or fern frond.
  2. Noun.  (zoology, anatomy) The spine or the vertebrae of the spine.
  3. Noun.  (ornithology) The central shaft of a feather.

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This entry was last updated on RefTopia from its source on 3/20/2012.