The Collaborative International Dictionary of English v.0.48:

Proven \Prov"en\, p. p. or a.
   Proved. "Accusations firmly proven in his mind." --Thackeray.
   [1913 Webster]

         Of this which was the principal charge, and was
         generally believed to beproven, he was acquitted.
                                                  --Jowett
                                                  (Thucyd. ).
   [1913 Webster]

   Not proven (Scots Law), a verdict of a jury that the guilt
      of the accused is not made out, though not disproved.
      --Mozley & W.
      [1913 Webster]

WordNet (r) 3.0 (2006):

proven
    adj 1: established beyond doubt; "a proven liar"; "a Soviet
           leader of proven shrewdness" [syn: proved, proven]
           [ant: unproved, unproven]