Source : Webster's Revised Unabridged Dictionary (1913)

Confirmatory \Con*firm"a*to*ry\, a. .
   Serving to confirm; corroborative.

         A fact confirmatory of the conclusion.   --I. Taylor.

   2. Pertaining to the rite of confirmation. --Compton.

Source : WordNet®

confirmatory
     adj : serving to support or corroborate; "collateral evidence"
           [syn: {collateral}, {confirmative}, {confirming}, {corroborative},
            {corroboratory}, {substantiating}, {substantiative}, {validating},
            {validatory}, {verificatory}, {verifying}]