Source : Webster's Revised Unabridged Dictionary (1913)

Rationalization \Ra`tion*al*i*za"tion\, n.
   The act or process of rationalizing.

Source : WordNet®

rationalization
     n 1: the cognitive process of making something seem consistent
          with or based on reason [syn: {rationalisation}]
     2: (psychiatry) a defense mechanism by which your true
        motivation is concealed by explaining your actions and
        feelings in a way that is not threatening [syn: {rationalisation}]
     3: (mathematics) the simplification of an expression or
        equation by eliminating radicals without changing the
        value of the expression or the roots of the equation [syn:
         {rationalisation}]
     4: the organization of a business according to scientific
        principles of management in order to increase efficiency
        [syn: {rationalisation}]
     5: systematic organization; the act of organizing something
        according to a system or a rationale [syn: {systematization},
         {systematisation}, {rationalisation}]