The Collaborative International Dictionary of English v.0.48:

Equivocal \E*quiv"o*cal\, a. [L. aequivocus: aequus equal + vox,
   vocis, word. See Equal, and Voice, and cf. Equivoque.]
   1. (Literally, called equally one thing or the other; hence:)
      Having two significations equally applicable; capable of
      double interpretation; of doubtful meaning; ambiguous;
      uncertain; as, equivocal words; an equivocal sentence.
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            For the beauties of Shakespeare are not of so dim or
            equivocal a nature as to be visible only to learned
            eyes.                                 --Jeffrey.
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   2. Capable of being ascribed to different motives, or of
      signifying opposite feelings, purposes, or characters;
      deserving to be suspected; as, his actions are equivocal.
      "Equivocal repentances." --Milton.
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   3. Uncertain, as an indication or sign; doubtful. "How
      equivocal a test." --Burke.
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   Equivocal chord (Mus.), a chord which can be resolved into
      several distinct keys; one whose intervals, being all
      minor thirds, do not clearly indicate its fundamental tone
      or root; the chord of the diminished triad, and the
      diminished seventh.

   Syn: Ambiguous; doubtful; uncertain; indeterminate.

   Usage: Equivocal, Ambiguous. We call an expression
          ambiguous when it has one general meaning, and yet
          contains certain words which may be taken in two
          different senses; or certain clauses which can be so
          connected with other clauses as to divide the mind
          between different views of part of the meaning
          intended. We call an expression equivocal when, taken
          as a whole, it conveys a given thought with perfect
          clearness and propriety, and also another thought with
          equal propriety and clearness. Such were the responses
          often given by the Delphic oracle; as that to
          Cr[oe]sus when consulting about a war with Persia: "If
          you cross the Halys, you will destroy a great empire."
          This he applied to the Persian empire, which lay
          beyond that river, and, having crossed, destroyed his
          own empire in the conflict. What is ambiguous is a
          mere blunder of language; what is equivocal is usually
          intended to deceive, though it may occur at times from
          mere inadvertence. Equivocation is applied only to
          cases where there is a design to deceive.
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