Source : Webster's Revised Unabridged Dictionary (1913)

Validation \Val`i*da"tion\, n. [Cf. F. validation.]
   The act of giving validity. [R.] --Knowles.

Source : WordNet®

validation
     n 1: the act of validating; finding or testing the truth of
          something [syn: {proof}, {substantiation}]
     2: the cognitive process of establishing a valid proof [syn: {establishment}]

Source : Free On-Line Dictionary of Computing

validation
     
        The stage in the {software life-cycle} at the end of the
        development process where software is evaluated to ensure that
        it complies with the requirements.
     
        (1995-02-14)