The Collaborative International Dictionary of English v.0.48:

Conviction \Con*vic"tion\ (k[o^]n*v[i^]k"sh[u^]n), n. [L.
   convictio proof: cf. F. conviction conviction (in sense 3 &
   4). See Convict, Convince.]
   1. The act of convicting; the act of proving, finding, or
      adjudging, guilty of an offense.
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            The greater certainty of conviction and the greater
            certainty of punishment.              --Hallam.
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   2. (Law) A judgment of condemnation entered by a court having
      jurisdiction; the act or process of finding guilty, or the
      state of being found guilty of any crime by a legal
      tribunal.
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            Conviction may accrue two ways.       --Blackstone.
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   3. The act of convincing of error, or of compelling the
      admission of a truth; confutation.
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            For all his tedious talk is but vain boast,
            Or subtle shifts conviction to evade. --Milton.
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   4. The state of being convinced or convicted; strong
      persuasion or belief; especially, the state of being
      convicted of sin, or by one's conscience.
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            To call good evil, and evil good, against the
            conviction of their own consciences.  --Swift.
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            And did you presently fall under the power of this
            conviction?                           --Bunyan.

   Syn: Conviction; persuasion.

   Usage: Conviction respects soley matters of belief or faith;
          persuasion respects matters of belief or practice.
          Conviction respects our most important duties;
          persuasion is frequently applied to matters of
          indifference. --Crabb. -- Conviction is the result of
          the [operation of the] understanding; persuasion, of
          the will. Conviction is a necessity of the mind,
          persuasion an acquiescence of the inclination. --C. J.
          Smith. -- Persuasion often induces men to act in
          opposition to their conviction of duty.
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Moby Thesaurus II by Grady Ward, 1.0:

92 Moby Thesaurus words for "conviction":
   anathematizing, arrogance, aspiration, assumption, assurance,
   assured faith, assuredness, belief, censure, certainty, certitude,
   cheerful expectation, cocksureness, condemnation, confidence,
   confidentness, courage, damnation, death sentence, death warrant,
   denouncement, denunciation, dependence, desire, doctrine, dogma,
   doom, doomed hope, excommunication, expectation, eye,
   fair prospect, faith, feeling, fervent hope, fixed opinion,
   good cheer, good hope, great expectations, guilty verdict,
   high hopes, hope, hopeful prognosis, hopefulness, hopes, hoping,
   hoping against hope, hubris, implicit belief, judgment,
   mature judgment, mind, opinion, overconfidence, oversureness,
   overweening, overweeningness, persuasion, poise, pomposity,
   position, positiveness, prayerful hope, presumption, pride,
   promise, proscription, prospect, prospects, rap, reliance,
   sanguine expectation, security, self-assurance, self-confidence,
   self-importance, self-reliance, sentence, sentiment,
   settled belief, settled judgment, staunch belief, steadfast faith,
   subjective certainty, sureness, surety, tenet, trust,
   unshaken confidence, verdict of guilty, view, well-grounded hope