Source : Webster's Revised Unabridged Dictionary (1913)

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.

   2. To lay the first color, coating, or preparation upon (a
      surface), as in painting; as, to prime a canvas, a wall.

   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.

   4. To trim or prune, as trees. [Obs. or Prov. Eng.]

   5. (Math.) To mark with a prime mark.

   {To prime a pump}, to charge a pump with water, in order to
      put it in working condition.

Priming \Prim"ing\, n.
   1. The powder or other combustible used to communicate fire
      to a charge of gunpowder, as in a firearm.

   2. (Paint.) The first coating of color, size, or the like,
      laid on canvas, or on a building, or other surface.

   3. (Steam Eng.) The carrying over of water, with the steam,
      from the boiler, as into the cylinder.

   {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.

Source : WordNet®

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}]
     3: the first or preliminary coat of paint or size applied to a
        surface [syn: {flat coat}, {ground}, {primer}, {primer
        coat}, {priming coat}, {undercoat}]