The Collaborative International Dictionary of English v.0.48:

Prove \Prove\, v. i.
   1. To make trial; to essay.
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   2. To be found by experience, trial, or result; to turn out
      to be; as, a medicine proves salutary; the report proves
      false. "The case proves mortal." --Arbuthnot.
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            So life a winter's morn may prove.    --Keble.
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   3. To succeed; to turn out as expected. [Obs.] "The
      experiment proved not." --Bacon.
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The Collaborative International Dictionary of English v.0.48:

Prove \Prove\, v. t. [imp. & p. p. Proved; p. pr. & vb. n.
   Proving.] [OE. prover, F. prouver, fr. L. probare to try,
   approve, prove, fr. probus good, proper. Cf. Probable,
   Proof, Probe.]
   1. To try or to ascertain by an experiment, or by a test or
      standard; to test; as, to prove the strength of gunpowder
      or of ordnance; to prove the contents of a vessel by a
      standard measure.
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            Thou hast proved mine heart.          --Ps. xvii. 3.
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   2. To evince, establish, or ascertain, as truth, reality, or
      fact, by argument, testimony, or other evidence.
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            They have inferred much from slender premises, and
            conjectured when they could not prove. --J. H.
                                                  Newman.
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   3. To ascertain or establish the genuineness or validity of;
      to verify; as, to prove a will.
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   4. To gain experience of the good or evil of; to know by
      trial; to experience; to suffer.
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            Where she, captived long, great woes did prove.
                                                  --Spenser.
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   5. (Arith.) To test, evince, ascertain, or verify, as the
      correctness of any operation or result; thus, in
      subtraction, if the difference between two numbers, added
      to the lesser number, makes a sum equal to the greater,
      the correctness of the subtraction is proved.
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   6. (Printing) To take a trial impression of; to take a proof
      of; as, to prove a page.
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   Syn: To try; verify; justify; confirm; establish; evince;
        manifest; show; demonstrate.
        [1913 Webster]

WordNet (r) 3.0 (2006):

prove
    v 1: be shown or be found to be; "She proved to be right"; "The
         medicine turned out to save her life"; "She turned up HIV
         positive" [syn: prove, turn out, turn up]
    2: establish the validity of something, as by an example,
       explanation or experiment; "The experiment demonstrated the
       instability of the compound"; "The mathematician showed the
       validity of the conjecture" [syn: prove, demonstrate,
       establish, show, shew] [ant: confute, disprove]
    3: provide evidence for; "The blood test showed that he was the
       father"; "Her behavior testified to her incompetence" [syn:
       testify, bear witness, prove, evidence, show]
    4: prove formally; demonstrate by a mathematical, formal proof
    5: put to the test, as for its quality, or give experimental use
       to; "This approach has been tried with good results"; "Test
       this recipe" [syn: test, prove, try, try out,
       examine, essay]
    6: increase in volume; "the dough rose slowly in the warm room"
       [syn: rise, prove]
    7: cause to puff up with a leaven; "unleavened bread" [syn:
       raise, leaven, prove]
    8: take a trial impression of
    9: obtain probate of; "prove a will"

Moby Thesaurus II by Grady Ward, 1.0:

134 Moby Thesaurus words for "prove":
   affirm, afford proof of, argue, ascertain, assay, attend, attest,
   audit, authenticate, back, back up, balance, balance the books,
   be found, bear out, become of, bespeak, betoken, bolster,
   bring home to, bring out, bring to test, buttress, certify, check,
   check and doublecheck, check out, check over, cinch,
   circumstantiate, clinch, collate, come about, come of, come out,
   confirm, corroborate, cross-check, cut and try, demonstrate,
   determine, develop, document, double-check, end, engrave, ensue,
   essay, establish, eventuate, evince, examine, experiment, fall out,
   fare, fix, follow, follow from, fortify, get out, give a try,
   give a tryout, have a case, have a go, hectograph, hold good,
   hold water, impress, imprint, indicate, inventory, issue,
   make good, make out, mimeograph, multigraph, nail down, overhaul,
   overprint, pan out, play around with, practice upon, print,
   probate, proof, prove to be, prove true, publish, pull,
   pull a proof, put out, put to bed, put to press, put to trial,
   ratify, recheck, reinforce, reissue, remove all doubt, reprint,
   research, result, road-test, run, run a sample, run off, sample,
   set at rest, settle, settle the matter, shake down, show, stamp,
   strengthen, strike, substantiate, support, sustain, take stock,
   taste, terminate, test, triple-check, try, try it on, try out,
   turn out, undergird, unfold, uphold, validate, verify, warrant,
   work out