1. Adjective.  From an external source; not innate or inherent, foreign.
  2. Adjective.  Accidental, additional, appearing casually.
  3. Adjective.  (genetics, medicine) Not congenital; acquired.
  4. Adjective.  (biology) Developing in an unusual place or from an unusual source.

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