The Collaborative International Dictionary of English v.0.48:

Purge \Purge\, v. i.
   1. To become pure, as by clarification.
      [1913 Webster]

   2. To have or produce frequent evacuations from the
      intestines, as by means of a cathartic.
      [1913 Webster]

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.
      [1913 Webster]

   2. (Med.) To operate on as, or by means of, a cathartic
      medicine, or in a similar manner.
      [1913 Webster]

   3. To clarify; to defecate, as liquors.
      [1913 Webster]

   4. To clear of sediment, as a boiler, or of air, as a steam
      pipe, by driving off or permitting escape.
      [1913 Webster]

   5. To clear from guilt, or from moral or ceremonial
      defilement; as, to purge one of guilt or crime.
      [1913 Webster]

            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:

Purge \Purge\, n. [Cf. F. purge. See Purge, v. t.]
   1. The act of purging.
      [1913 Webster]

            The preparative for the purge of paganism of the
            kingdom of Northumberland.            --Fuller.
      [1913 Webster]

   2. That which purges; especially, a medicine that evacuates
      the intestines; a cathartic. --Arbuthnot.
      [1913 Webster]

WordNet (r) 3.0 (2006):

purge
    n 1: the act of clearing yourself (or another) from some stigma
         or charge [syn: purge, purging, purgation]
    2: an act of removing by cleansing; ridding of sediment or other
       undesired elements [syn: purge, purging]
    3: an abrupt or sudden removal of a person or group from an
       organization or place; "he died in a purge by Stalin"
    v 1: oust politically; "Deng Xiao Ping was purged several times
         throughout his lifetime" [ant: rehabilitate]
    2: clear of a charge
    3: make pure or free from sin or guilt; "he left the monastery
       purified" [syn: purify, purge, sanctify]
    4: rid of impurities; "purge the water"; "purge your mind"
    5: rinse, clean, or empty with a liquid; "flush the wound with
       antibiotics"; "purge the old gas tank" [syn: flush,
       scour, purge]
    6: eject the contents of the stomach through the mouth; "After
       drinking too much, the students vomited"; "He purged
       continuously"; "The patient regurgitated the food we gave him
       last night" [syn: vomit, vomit up, purge, cast,
       sick, cat, be sick, disgorge, regorge, retch,
       puke, barf, spew, spue, chuck, upchuck, honk,
       regurgitate, throw up] [ant: keep down]
    7: excrete or evacuate (someone's bowels or body); "The doctor
       decided that the patient must be purged"

Moby Thesaurus II by Grady Ward, 1.0:

386 Moby Thesaurus words for "purge":
   BM, abolishment, abolition, absolve, abstergent, abstersion,
   abstract, account for, acquit, amnesty, annihilate, annihilation,
   annulment, aperient, assassinate, assassination, bandage, bathe,
   bereave of life, bleach, bloody flux, bloody murder, blow,
   blow out, bowdlerization, bowdlerize, bowel movement, break,
   bumping-off, bust, care for, carminative, carry away, carry off,
   cashier, cashiering, cast off, cast out, catharsis, cathartic,
   chloroform, choking, choking off, chuck, clean, clean out,
   clean up, cleaner, cleaning, cleaning agent, cleaning solvent,
   cleanse, cleanse away, cleanser, cleansing, cleansing cream, clear,
   clear away, clear off, clear out, clear the decks, clearance,
   cold cream, crap, cream, cry sour grapes, cure, cut down, cut off,
   cut out, debar, deconsecrate, deconsecration, decontaminate,
   defecate, defecation, defenestration, defrock, defrocking,
   dejection, deliver, deliverance, delouse, dentifrice, deplete,
   deport, deportation, deposal, depose, deposition, deprivation,
   deprive of life, depurant, depurate, deracinate, deracination,
   destigmatize, destroy, detachment, deterge, detergent, detersion,
   dethrone, dethronement, diagnose, diarrhea, disbar, disbarment,
   disbarring, discard, discharge, discrown, discrownment,
   disenthrone, disenthronement, disjunction, dismiss, dismissal,
   dispatch, dispel, dispense from, displace, displacement, disposal,
   dispose of, disposition, diuretic, do away with, do for,
   do justice to, do to death, doctor, drain, drum out, dry cleaning,
   dry-clean, dust, dust off, dysentery, eject, ejection, elide,
   eliminate, elimination, emetic, emotional release, empty,
   empty out, end, enema, eradicate, eradication, erase, evacuate,
   evacuation, exclude, excommunicate, excommunication, exculpate,
   excuse, execute, exempt, exempt from, exhaust, exile, exonerate,
   expatriate, expatriation, expel, explain, expulsion, expunge,
   expurgate, expurgation, exterminate, extermination, extinction,
   extinguishment, extirpate, extirpation, finish, finish off, firing,
   fling off, flux, forced resignation, forgive, foul play, free,
   free from, freeing, freshen, get quit of, get rid of, get shut of,
   give absolution, give care to, give release, give respite,
   give the gate, grant amnesty to, grant immunity, grant remission,
   heal, holystone, homicide, immolate, impeachment, intermission,
   intermit, justify, kick upstairs, kicking upstairs, kill, killing,
   launch into eternity, laxative, let go, let off, lientery,
   liquidate, liquidation, loose bowels, lotion, lustrate, lustration,
   lynch, make away with, manslaughter, martyr, martyrize, massage,
   minister to, mouthwash, movement, murder, nauseant, negation,
   nonpros, nullification, nurse, operate on, ostracism, oust, ouster,
   ousting, outlaw, outlawing, outlawry, overthrow, overthrowal,
   pardon, pension, pension off, pensioning off, physic, pick out,
   plaster, poison, poultice, pumice stone, purgation, purgative,
   purge away, purging, purification, purifier, purify, put away,
   put down, put to death, put to sleep, quash the charge,
   rationalize, read out of, reform, rehabilitate, reinstate, release,
   remedy, remit, removal, remove, remove from life,
   remove from office, reprieve, respite, restore, retire, retirement,
   rid, riddance, rinse, root out, root up, rooting out, rout out,
   rub, runs, sacrifice, scavenge, scour out, set free, severance,
   shake off, shampoo, shit, shits, shoo, shrive, shut out, silencing,
   slaughter, slay, snuffing out, soap, solvent, splint, spruce,
   starve, steam cleaning, steam-clean, stifling, stool,
   strangulation, strap, strike off, strike out, strip of office,
   strip of rank, suffocation, superannuate, superannuation,
   suppression, surcease, suspend, suspension, sweep away, sweep out,
   sweeten, synthetic detergent, take life, take off, throw off,
   throw over, throw overboard, thuggee, thuggery, thuggism, tidy,
   tolerate, tooth powder, toothpaste, treat, trots, turistas,
   unchurch, unchurching, unclog, undeceive, unfoul, unfrock,
   unfrocking, unsaddle, unseat, unseating, unthrone, uproot,
   uprooting, vent, vindicate, void, voidance, voiding, warrant, wash,
   wash out, weed out, whiten, whitewash, wipe, wipe off, wipe out,
   wipe up, withdraw the charge, withdrawal