The Collaborative International Dictionary of English v.0.48:

Witness \Wit"ness\, n. [AS. witness, gewitnes, from witan to
   know. [root]133. See Wit, v. i.]
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   1. Attestation of a fact or an event; testimony.
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            May we with . . . the witness of a good conscience,
            pursue him with any further revenge?  --Shak.
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            If I bear witness of myself, my witness is not true.
                                                  --John v. 31.
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   2. That which furnishes evidence or proof.
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            Laban said to Jacob, . . . This heap be witness, and
            this pillar be witness.               --Gen. xxxi.
                                                  51, 52.
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   3. One who is cognizant; a person who beholds, or otherwise
      has personal knowledge of, anything; as, an eyewitness; an
      earwitness. "Thyself art witness I am betrothed." --Shak.
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            Upon my looking round, I was witness to appearances
            which filled me with melancholy and regret. --R.
                                                  Hall.
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   4. (Law)
      (a) One who testifies in a cause, or gives evidence before
          a judicial tribunal; as, the witness in court agreed
          in all essential facts.
      (b) One who sees the execution of an instrument, and
          subscribes it for the purpose of confirming its
          authenticity by his testimony; one who witnesses a
          will, a deed, a marriage, or the like.
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   Privileged witnesses. (Law) See under Privileged.

   With a witness, effectually; to a great degree; with great
      force, so as to leave some mark as a testimony. [Colloq.]
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            This, I confess, is haste with a witness. --South.
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