The Collaborative International Dictionary of English v.0.48:

Revenge \Re*venge"\, v. t. [imp. & p. p. Revenged, p. pr. &
   vb. n. Revenging.] [OF. revengier, F. revancher; pref. re-
   re- + OF. vengier to avenge, revenge, F. venger, L.
   vindicare. See Vindicate, Vengerance, and cf.
   Revindicate.]
   1. To inflict harm in return for, as an injury, insult, etc.;
      to exact satisfaction for, under a sense of injury; to
      avenge; -- followed either by the wrong received, or by
      the person or thing wronged, as the object, or by the
      reciprocal pronoun as direct object, and a preposition
      before the wrong done or the wrongdoer.
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            To revenge the death of our fathers.  --Ld. Berners.
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            The gods are just, and will revenge our cause.
                                                  --Dryden.
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            Come, Antony, and young Octavius, come,
            Revenge yourselves alone on Cassius.  --Shak.
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   2. To inflict injury for, in a spiteful, wrong, or malignant
      spirit; to wreak vengeance for maliciously.
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   Syn: To avenge; vindicate. See Avenge.
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The Collaborative International Dictionary of English v.0.48:

Revenge \Re*venge"\, v. i.
   To take vengeance; -- with upon. [Obs.] "A bird that will
   revenge upon you all." --Shak.
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The Collaborative International Dictionary of English v.0.48:

Revenge \Re*venge"\, n.
   1. The act of revenging; vengeance; retaliation; a returning
      of evil for evil.
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            Certainly, in taking revenge, a man is even with his
            enemy; but in passing it over he is superior.
                                                  --Bacon.
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   2. The disposition to revenge; a malignant wishing of evil to
      one who has done us an injury.
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            Revenge now goes
            To lay a complot to betray thy foes.  --Shak.
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            The indulgence of revenge tends to make men more
            savage and cruel.                     --Kames.
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WordNet (r) 3.0 (2006):

revenge
    n 1: action taken in return for an injury or offense [syn:
         retaliation, revenge]
    v 1: take revenge for a perceived wrong; "He wants to avenge the
         murder of his brother" [syn: revenge, avenge,
         retaliate]