Source : Webster's Revised Unabridged Dictionary (1913)

Escape \Es*cape"\, n.
   1. The act of fleeing from danger, of evading harm, or of
      avoiding notice; deliverance from injury or any evil;
      flight; as, an escape in battle; a narrow escape; also,
      the means of escape; as, a fire escape.

            I would hasten my escape from the windy storm. --Ps.
                                                  lv. 8.

   2. That which escapes attention or restraint; a mistake; an
      oversight; also, transgression. [Obs.]

            I should have been more accurate, and corrected all
            those former escapes.                 --Burton.

   3. A sally. ``Thousand escapes of wit.'' --Shak.

   4. (Law) The unlawful permission, by a jailer or other
      custodian, of a prisoner's departure from custody.

   Note: Escape is technically distinguishable from prison
         breach, which is the unlawful departure of the prisoner
         from custody, escape being the permission of the
         departure by the custodian, either by connivance or
         negligence. The term escape, however, is applied by
         some of the old authorities to a departure from custody
         by stratagem, or without force. --Wharton.

   5. (Arch.) An apophyge.

   6. Leakage or outflow, as of steam or a liquid.

   7. (Elec.) Leakage or loss of currents from the conducting
      wires, caused by defective insulation.

   {Escape pipe} (Steam Boilers), a pipe for carrying away steam
      that escapes through a safety valve.

   {Escape valve} (Steam Engine), a relief valve; a safety
      valve. See under {Relief}, and {Safety}.

   {Escape wheel} (Horol.), the wheel of an escapement.

Source : WordNet®

escape wheel
     n : gear that engages a rocking lever