The Collaborative International Dictionary of English v.0.48:

Defecate \Def"e*cate\, v. t. [imp. & p. p. Defecated; p. pr. &
   vb. n. Defecating.]
   1. To clear from impurities, as lees, dregs, etc.; to
      clarify; to purify; to refine.
      [1913 Webster]

            To defecate the dark and muddy oil of amber.
                                                  --Boyle.
      [1913 Webster]

   2. To free from extraneous or polluting matter; to clear; to
      purify, as from that which materializes.
      [1913 Webster]

            We defecate the notion from materiality. --Glanvill.
      [1913 Webster]

            Defecated from all the impurities of sense. --Bp.
                                                  Warburton.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Defecate \Def"e*cate\, a. [L. defaecatus, p. p. of defaecare to
   defecate; de- + faex, faecis, dregs, lees.]
   Freed from anything that can pollute, as dregs, lees, etc.;
   refined; purified.
   [1913 Webster]

         Till the soul be defecate from the dregs of sense.
                                                  --Bates.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Defecate \Def"e*cate\, v. i.
   1. To become clear, pure, or free. --Goldsmith.
      [1913 Webster]

   2. To void excrement.
      [1913 Webster]

WordNet (r) 3.0 (2006):

defecate
    v 1: have a bowel movement; "The dog had made in the flower
         beds" [syn: stool, defecate, shit, take a shit,
         take a crap, ca-ca, crap, make]

Moby Thesaurus II by Grady Ward, 1.0:

32 Moby Thesaurus words for "defecate":
   blow, blow out, ca-ca, clean out, clear, clear away, clear off,
   clear out, clear the decks, crap, deplete, drain, dung, eliminate,
   empty, empty out, evacuate, excrete, exhaust, number two, purge,
   remove, scour out, shit, spend a penny, stool, sweep out,
   take a shit, unclog, unfoul, vent, void