The Collaborative International Dictionary of English v.0.48:

Imprecate \Im"pre*cate\, v. t. [imp. & p. p. Imprecated; p.
   pr. & vb. n. Imprecating.] [L. imprecatus, p. p. of
   imprecari to imprecate; pref. im- in, on + precari to pray.
   See Pray.]
   1. To call down by prayer, as something hurtful or
      calamitous.
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            Imprecate the vengeance of Heaven on the guilty
            empire.                               --Mickle.
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   2. To invoke evil upon; to curse; to swear at.
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            In vain we blast the ministers of Fate,
            And the forlorn physicians imprecate. --Rochester.
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