The Collaborative International Dictionary of English v.0.48:

Prime \Prime\, v. t. [imp. & p. p. Primed; p. pr. & vb. n.
   Priming.] [From Prime, a.]
   1. To apply priming to, as a musket or a cannon; to apply a
      primer to, as a metallic cartridge.
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   2. To lay the first color, coating, or preparation upon (a
      surface), as in painting; as, to prime a canvas, a wall.
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   3. To prepare; to make ready; to instruct beforehand; to
      post; to coach; as, to prime a witness; the boys are
      primed for mischief. [Colloq.] --Thackeray.
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   4. To trim or prune, as trees. [Obs. or Prov. Eng.]
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   5. (Math.) To mark with a prime mark.
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   To prime a pump, to charge a pump with water, in order to
      put it in working condition.
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The Collaborative International Dictionary of English v.0.48:

Priming \Prim"ing\, n.
   1. The powder or other combustible used to communicate fire
      to a charge of gunpowder, as in a firearm.
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   2. (Paint.) The first coating of color, size, or the like,
      laid on canvas, or on a building, or other surface.
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   3. (Steam Eng.) The carrying over of water, with the steam,
      from the boiler, as into the cylinder.
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   Priming of the tide. See Lag of the tide, under 2d Lag.


   Priming tube, a small pipe, filled with a combustible
      composition for firing cannon.

   Priming valve (Steam Eng.), a spring safety valve applied
      to the cylinder of a steam engine for discharging water
      carried into the cylinder by priming.

   Priming wire, a pointed wire used to penetrate the vent of
      a piece, for piercing the cartridge before priming.
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WordNet (r) 3.0 (2006):

priming
    n 1: the act of making something ready
    2: any igniter that is used to initiate the burning of a
       propellant [syn: fuse, fuze, fusee, fuzee, primer,
       priming]
    3: the first or preliminary coat of paint or size applied to a
       surface [syn: flat coat, ground, primer, priming,
       primer coat, priming coat, undercoat]