Source : Webster's Revised Unabridged Dictionary (1913)

Purgation \Pur*ga"tion\, n. [L. purgatio: cf. F. purgation. See
   {Purge}.]
   1. The act of purging; the act of clearing, cleansing, or
      putifying, by separating and carrying off impurities, or
      whatever is superfluous; the evacuation of the bowels.

   2. (Law) The clearing of one's self from a crime of which one
      was publicly suspected and accused. It was either
      canonical, which was prescribed by the canon law, the form
      whereof used in the spiritual court was, that the person
      suspected take his oath that he was clear of the matter
      objected against him, and bring his honest neighbors with
      him to make oath that they believes he swore truly; or
      vulgar, which was by fire or water ordeal, or by combat.
      See {Ordeal}. --Wharton.

            Let him put me to my purgation.       --Shak.

Source : WordNet®

purgation
     n 1: purging the body by the use of a cathartic to stimulate
          evacuation of the bowels [syn: {catharsis}, {katharsis}]
     2: a ceremonial cleansing from defilement or uncleanness by the
        performance of appropriate rites [syn: {purification}]
     3: the act of clearing yourself (or another) from some stigma
        or charge [syn: {purge}, {purging}]