The Collaborative International Dictionary of English v.0.48:

Pursuivant \Pur"sui*vant\, n. [F. poursuivant, fr. poursuivre.
   See Pursue, and cf. Pursuant.] [Written also
   poursuivant.]
   1. (Heralds' College) A functionary of lower rank than a
      herald, but discharging similar duties; -- called also
      pursuivant at arms; an attendant of the heralds. Also
      used figuratively.
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            The herald Hope, forerunning Fear,
            And Fear, the pursuivant of Hope.     --Longfellow.
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   2. The king's messenger; a state messenger.
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            One pursuivant who attempted to execute a warrant
            there was murdered.                   --Macaulay.
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