The Collaborative International Dictionary of English v.0.48:

Purge \Purge\, v. t. [imp. & p. p. Purged; p. pr. & vb. n.
   Purging.] [F. purger, L. purgare; purus pure + agere to
   make, to do. See Pure, and Agent.]
   1. To cleanse, clear, or purify by separating and carrying
      off whatever is impure, heterogeneous, foreign, or
      superfluous. "Till fire purge all things new." --Milton.
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   2. (Med.) To operate on as, or by means of, a cathartic
      medicine, or in a similar manner.
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   3. To clarify; to defecate, as liquors.
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   4. To clear of sediment, as a boiler, or of air, as a steam
      pipe, by driving off or permitting escape.
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   5. To clear from guilt, or from moral or ceremonial
      defilement; as, to purge one of guilt or crime.
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            When that he hath purged you from sin. --Chaucer.
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            Purge me with hyssop, and I shall be clean. --Ps.
                                                  li. 7.
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   6. (Law) To clear from accusation, or the charge of a crime
      or misdemeanor, as by oath or in ordeal.
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   7. To remove in cleansing; to deterge; to wash away; -- often
      followed by away.
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            Purge away our sins, for thy name's sake. --Ps.
                                                  lxxix. 9.
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            We 'll join our cares to purge away
            Our country's crimes.                 --Addison.
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The Collaborative International Dictionary of English v.0.48:

Purging \Pur"ging\, a.
   That purges; cleansing.
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   Purging flax (Bot.), an annual European plant of the genus
      Linum (Linum catharticum); dwarf wild flax; -- so
      called from its use as a cathartic medicine.
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The Collaborative International Dictionary of English v.0.48:

Purging \Pur"ging\, n. (Med.)
   The act of cleansing; excessive evacuations; especially,
   diarrhea.
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WordNet (r) 3.0 (2006):

purging
    adj 1: serving to purge or rid of sin; "purgatorial rites" [syn:
           purgatorial, purging, purifying]
    n 1: an act of removing by cleansing; ridding of sediment or
         other undesired elements [syn: purge, purging]
    2: the act of clearing yourself (or another) from some stigma or
       charge [syn: purge, purging, purgation]

Moby Thesaurus II by Grady Ward, 1.0:

73 Moby Thesaurus words for "purging":
   absolution, abstergent, abstersion, acquittal, acquittance,
   assassination, bloody murder, bowdlerization, bumping-off,
   catharsis, cathartic, cleaning, cleansing, clearance, clearing,
   compurgation, deliverance, depurative, destigmatization,
   destigmatizing, detergent, detersion, discharge, disculpation,
   dismissal, diuretic, dry cleaning, elimination, emetic,
   emotional release, exculpation, excuse, exoneration, explanation,
   expurgation, expurgatory, forgiveness, foul play, freeing,
   homicide, intermission, justification, liquidation, lustral,
   lustration, manslaughter, murder, pardon, purgation, purgative,
   purge, purification, purificatory, purifying, quietus, quittance,
   rationalization, rehabilitation, reinstatement, release, remission,
   removal, reprieve, respite, restoration, steam cleaning, surcease,
   suspension, thuggee, thuggery, thuggism, verdict of acquittal,
   vindication