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.
      [1913 Webster]

            Purge me with hyssop, and I shall be clean. --Ps.
                                                  li. 7.
      [1913 Webster]

   6. (Law) To clear from accusation, or the charge of a crime
      or misdemeanor, as by oath or in ordeal.
      [1913 Webster]

   7. To remove in cleansing; to deterge; to wash away; -- often
      followed by away.
      [1913 Webster]

            Purge away our sins, for thy name's sake. --Ps.
                                                  lxxix. 9.
      [1913 Webster]

            We 'll join our cares to purge away
            Our country's crimes.                 --Addison.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Purging \Pur"ging\, a.
   That purges; cleansing.
   [1913 Webster]

   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.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Purging \Pur"ging\, n. (Med.)
   The act of cleansing; excessive evacuations; especially,
   diarrhea.
   [1913 Webster]

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]