The Collaborative International Dictionary of English v.0.48:

Acknow \Ac*know"\ ([a^]k*n[=o]"), v. t. [Pref. a- + know; AS.
   oncn[=a]wan.]
   1. To recognize. [Obs.] "You will not be acknown, sir." --B.
      Jonson.
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   2. To acknowledge; to confess. [Obs.] --Chaucer.
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   To be acknown (often with of or on), to acknowledge; to
      confess. [Obs.]
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            We say of a stubborn body that standeth still in the
            denying of his fault, This man will not acknowledge
            his fault, or, He will not be acknown of his fault.
                                                  --Sir T. More.
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