Source : Webster's Revised Unabridged Dictionary (1913)

Injection \In*jec"tion\, n. [L. injectio : cf.F. injection.]
   1. The act of injecting or throwing in; -- applied
      particularly to the forcible throwing in of a liquid, or
      a["e]riform body, by means of a syringe, pump, etc.

   2. That which is injected; especially, a liquid medicine
      thrown into a cavity of the body by a syringe or pipe; a
      clyster; an enema. --Mayne.

   3. (Anat.)
      (a) The act or process of filling vessels, cavities, or
          tissues with a fluid or other substance.
      (b) A specimen prepared by injection.

   4. (Steam Eng.)
      (a) The act of throwing cold water into a condenser to
          produce a vacuum.
      (b) The cold water thrown into a condenser.

   {Injection cock}, or {Injection valve} (Steam Eng.), the cock
      or valve through which cold water is admitted into a
      condenser.

   {Injection condenser}. See under {Condenser}.

   {Injection pipe}, the pipe through which cold water is
      through into the condenser of a steam engine.