The Collaborative International Dictionary of English v.0.48:

Pickle \Pic"kle\, n. [Cf. D. pekel. Probably a dim. fr. Pick,
   v. t., alluding to the cleaning of the fish.]
   1.
      (a) A solution of salt and water, in which fish, meat,
          etc., may be preserved or corned; brine.
      (b) Vinegar, plain or spiced, used for preserving
          vegetables, fish, eggs, oysters, etc.
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   2. Any article of food which has been preserved in brine or
      in vinegar.
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   3. (Founding) A bath of dilute sulphuric or nitric acid,
      etc., to remove burnt sand, scale rust, etc., from the
      surface of castings, or other articles of metal, or to
      brighten them or improve their color.
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   4. A troublesome child; as, a little pickle. [Colloq.]
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   To be in a pickle, to be in disagreeable position; to be in
      a condition of embarrassment, difficulty, or disorder.
      "How cam'st thou in this pickle?" --Shak.

   To put a rod in pickle, to prepare a particular reproof,
      punishment, or penalty for future application.
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