The Collaborative International Dictionary of English v.0.48:

Disprove \Dis*prove"\, v. t. [imp. & p. p. Disproved; p. pr. &
   vb. n. Disproving.] [Pref. dis- + prove: cf. OF.
   desprover.]
   1. To prove to be false or erroneous; to confute; to refute.
      [1913 Webster]

            That false supposition I advanced in order to
            disprove it.                          --Atterbury.
      [1913 Webster]

   2. To disallow; to disapprove of. [Obs.] --Stirling.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

22 Moby Thesaurus words for "disproved":
   belied, confounded, confuted, deflated, denied, discarded,
   discredited, dismissed, disputed, exploded, exposed, impugned,
   invalidated, negated, negatived, overthrown, overturned, punctured,
   refuted, rejected, shown up, upset