The Collaborative International Dictionary of English v.0.48:

Instance \In"stance\, n. [F. instance, L. instantia, fr.
   instans. See Instant.]
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   1. The act or quality of being instant or pressing; urgency;
      solicitation; application; suggestion; motion.
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            Undertook at her instance to restore them. --Sir W.
                                                  Scott.
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   2. That which is instant or urgent; motive. [Obs.]
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            The instances that second marriage move
            Are base respects of thrift, but none of love.
                                                  --Shak.
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   3. Occasion; order of occurrence.
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            These seem as if, in the time of Edward I., they
            were drawn up into the form of a law, in the first
            instance.                             --Sir M. Hale.
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   4. That which offers itself or is offered as an illustrative
      case; something cited in proof or exemplification; a case
      occurring; an example; as, we could find no instance of
      poisoning in the town within the past year.
      [1913 Webster +PJC]

            Most remarkable instances of suffering. --Atterbury.
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   5. A token; a sign; a symptom or indication. --Shak.
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   Causes of instance, those which proceed at the solicitation
      of some party. --Hallifax.

   Court of first instance, the court by which a case is first
      tried.

   For instance, by way of example or illustration; for
      example.

   Instance Court (Law), the Court of Admiralty acting within
      its ordinary jurisdiction, as distinguished from its
      action as a prize court.

   Syn: Example; case. See Example.
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WordNet (r) 3.0 (2006):

for instance
    adv 1: as an example; "take ribbon snakes, for example" [syn:
           for example, for instance, e.g.]