Source : Webster's Revised Unabridged Dictionary (1913)

Free will \Free will\
   1. A will free from improper coercion or restraint.

            To come thus was I not constrained, but did On my
            free will.                            --Shak.

   2. The power asserted of moral beings of willing or choosing
      without the restraints of physical or absolute necessity.

Source : WordNet®

free will
     n : the power of making free choices unconstrained by external
         agencies [syn: {discretion}]