The Collaborative International Dictionary of English v.0.48:

Test \Test\, v. t. [imp. & p. p. Tested; p. pr. & vb. n.
   Testing.]
   1. (Metal.) To refine, as gold or silver, in a test, or
      cupel; to subject to cupellation.
      [1913 Webster]

   2. To put to the proof; to prove the truth, genuineness, or
      quality of by experiment, or by some principle or
      standard; to try; as, to test the soundness of a
      principle; to test the validity of an argument.
      [1913 Webster]

            Experience is the surest standard by which to test
            the real tendency of the existing constitution.
                                                  --Washington.
      [1913 Webster]

   3. (Chem.) To examine or try, as by the use of some reagent;
      as, to test a solution by litmus paper.
      [1913 Webster]

   4. To administer a test[8] to (someone) for the purpose of
      ascertaining a person's knowledge or skill; especially, in
      academic settings, to determine how well a student has
      learned the subject matter of a course of instruction.
      [PJC]
      [1913 Webster]

WordNet (r) 3.0 (2006):

tested
    adj 1: tested and proved useful or correct; "a tested method"
           [syn: tested, tried, well-tried]
    2: tested and proved to be reliable [syn: tested, time-
       tested, tried, tried and true]

Moby Thesaurus II by Grady Ward, 1.0:

50 Moby Thesaurus words for "tested":
   ascertained, assured, attested, certified, committed, confirmed,
   constant, decided, dedicated, dependable, determinate, determined,
   devoted, established, faithful, faithworthy, fast, fixed,
   guaranteed, in the bag, incorruptible, inviolable, made sure,
   nailed down, on ice, open-and-shut, proved, proven, reliable,
   responsible, secure, set, settled, stated, staunch, steadfast,
   straight, sure, to be trusted, tried, tried and true, true,
   trustable, trustworthy, trusty, unfalse, unperfidious,
   untreacherous, verified, warranted