Source : Webster's Revised Unabridged Dictionary (1913)

Throttle \Throt"tle\, n. [Dim. of throat. See {Throat}.]
   1. The windpipe, or trachea; the weasand. --Sir W. Scott.

   2. (Steam Engine) The throttle valve.

   {Throttle lever} (Steam Engine), the hand lever by which a
      throttle valve is moved, especially in a locomotive.

   {Throttle valve} (Steam Engine), a valve moved by hand or by
      a governor for regulating the supply of steam to the steam
      chest. In one form it consists of a disk turning on a
      transverse axis.

Throttle \Throt"tle\, v. t. [imp. & p. p. {Throttled}; p. pr. &
   vb. n. {Throttling}.]
   1. To compress the throat of; to choke; to strangle.

            Grant him this, and the Parliament hath no more
            freedom than if it sat in his noose, which, when he
            pleases to draw together with one twitch of his
            negative, shall throttle a whole nation, to the wish
            of Caligula, in one neck.             --Milton.

   2. To utter with breaks and interruption, in the manner of a
      person half suffocated. [R.]

            Throttle their practiced accent in their fears.
                                                  --Shak.

   3. To shut off, or reduce flow of, as steam to an engine.

Throttle \Throt"tle\, v. i.
   1. To have the throat obstructed so as to be in danger of
      suffocation; to choke; to suffocate.

   2. To breathe hard, as when nearly suffocated.

Source : WordNet®

throttle
     n 1: a valve that regulates the supply of fuel to the engine
          [syn: {accelerator}, {throttle valve}]
     2: a pedal that controls the throttle valve; "he stepped on the
        gas" [syn: {accelerator}, {accelerator pedal}, {gas pedal},
         {gas}, {gun}]

throttle
     v 1: place limits on (extent or access); "restrict the use of
          this parking lot"; "limit the time you can spend with
          your friends" [syn: {restrict}, {restrain}, {trammel}, {limit},
           {bound}, {confine}]
     2: kill by squeezing the throat of so as to cut off the air;
        "he tried to strangle his opponent"; "A man in Boston has
        been strangling several dozen prostitutes" [syn: {strangle},
         {strangulate}]
     3: reduce the air supply; "choke a carburetor" [syn: {choke}]