The Collaborative International Dictionary of English v.0.48:

Confess \Con*fess"\, v. t. [imp. & p. p. Confessed; p. pr. &
   vb. n. Confessing.] [F. confesser, fr. L. confessus, p. p.
   of confiteri to confess; con- + fateri to confess; akin to
   fari to speak. See 2d Ban, Fame.]
   1. To make acknowledgment or avowal in a matter pertaining to
      one's self; to acknowledge, own, or admit, as a crime, a
      fault, a debt.
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            And there confess
            Humbly our faults, and pardon beg.    --Milton.
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            I must confess I was most pleased with a beautiful
            prospect that none of them have mentioned.
                                                  --Addison.
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   2. To acknowledge faith in; to profess belief in.
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            Whosoever, therefore, shall confess me before men,
            him will I confess, also, before my Father which is
            in heaven.                            --Matt. x. 32.
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            For the Sadducees say that there is no resurrection,
            neither angel, nor spirit; but the Pharisees confess
            both.                                 --Acts xxiii.
                                                  8.
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   3. To admit as true; to assent to; to acknowledge, as after a
      previous doubt, denial, or concealment.
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            I never gave it him. Send for him hither,
            And let him confess a truth.          --Shak.
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            As I confess it needs must be.        --Tennyson.
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            As an actor confessed without rival to shine.
                                                  --Goldsmith.
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   4. (Eccl.)
      (a) To make known or acknowledge, as one's sins to a
          priest, in order to receive absolution; -- sometimes
          followed by the reflexive pronoun.
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                Our beautiful votary took an opportunity of
                confessing herself to this celebrated father.
                                                  --Addison.
      (b) To hear or receive such confession; -- said of a
          priest.
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                He . . . heard mass, and the prince, his son,
                with him, and the most part of his company were
                confessed.                        --Ld. Berners.
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   5. To disclose or reveal, as an effect discloses its cause;
      to prove; to attest.
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            Tall thriving trees confessed the fruitful mold.
                                                  --Pope.

   Syn: Admit; grant; concede; avow; own; assent; recognize;
        prove; exhibit; attest.

   Usage: To Confess, Acknowledge, Avow. Acknowledge is
          opposed to conceal. We acknowledge what we feel must
          or ought to be made known. (See Acknowledge.) Avow
          is opposed to withhold. We avow when we make an open
          and public declaration, as against obloquy or
          opposition; as, to avow one's principles; to avow
          one's participation in some act. Confess is opposed to
          deny. We confess (in the ordinary sense of the word)
          what we feel to have been wrong; as, to confess one's
          errors or faults. We sometimes use confess and
          acknowledge when there is no admission of our being in
          the wrong; as, this, I confess, is my opinion; I
          acknowledge I have always thought so; but in these
          cases we mean simply to imply that others may perhaps
          think us in the wrong, and hence we use the words by
          way of deference to their opinions. It was in this way
          that the early Christians were led to use the Latin
          confiteor and confessio fidei to denote the public
          declaration of their faith in Christianity; and hence
          the corresponding use in English of the verb confess
          and the noun confession.
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The Collaborative International Dictionary of English v.0.48:

Confess \Con*fess"\, v. i.
   1. To make confession; to disclose sins or faults, or the
      state of the conscience.
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            Every tongue shall confess to God.    --Rom. xiv.
                                                  11.
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   2. To acknowledge; to admit; to concede.
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            But since
            (And I confess with right) you think me bound.
                                                  --Tennyson.
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WordNet (r) 3.0 (2006):

confess
    v 1: confess to a punishable or reprehensible deed, usually
         under pressure [syn: confess, squeal, fink]
    2: admit (to a wrongdoing); "She confessed that she had taken
       the money" [syn: concede, profess, confess]
    3: confess to God in the presence of a priest, as in the
       Catholic faith

Moby Thesaurus II by Grady Ward, 1.0:

84 Moby Thesaurus words for "confess":
   absolve, accept, account for, accredit with, accrete to,
   acknowledge, administer absolution, administer extreme unction,
   admit, admit everything, affirm, agree provisionally, allow,
   apply to, ascribe to, assent grudgingly, assert, asseverate,
   assign to, attach to, attribute to, aver, avouch, avow, blame,
   blame for, blame on, bring home to, charge on, charge to,
   come clean, concede, confirm, connect with, cop a plea,
   credit with, declare, disclose, divulge, express general agreement,
   express the belief, fasten upon, father upon, fix on, fix upon,
   go along with, grant, hang on, hear confession, impute to, lay to,
   let on, make confession, not oppose, open up, out with it, own,
   own up, pin on, pinpoint, place upon, plead guilty, point to,
   profess, receive absolution, recognize, refer to, reveal,
   saddle on, saddle with, set down to, settle upon, shrive, spill,
   spill it, spit it out, state, swear, tell all, tell the truth,
   testify, vow, warrant, yield