The Collaborative International Dictionary of English v.0.48:

Attest \At"test"\, v. t. [imp. & p. p. Attested; p. pr. & vb.
   n. Attesting.] [L. attestari; ad + testari to bear witness:
   cf. F. attester.]
   1. To bear witness to; to certify; to affirm to be true or
      genuine; as, to attest the truth of a writing, a copy of
      record.
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            Facts . . . attested by particular pagan authors.
                                                  --Addison.
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   2. To give proof of; to manifest; as, the ruins of Palmyra
      attest its ancient magnificence.
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   3. To call to witness; to invoke. [Archaic]
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            The sacred streams which Heaven's imperial state
            Attests in oaths, and fears to violate. --Dryden.
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