The Collaborative International Dictionary of English v.0.48:

Egest \E*gest"\, v. t. [L. egestus, p. p. of egerere to carry
   out, to discharge; e out + gerere to carry.] (Physiol.)
   To cast or throw out; to void, as excrement; to excrete, as
   the indigestible matter of the food; in an extended sense, to
   excrete by the lungs, skin, or kidneys.
   [1913 Webster]

WordNet (r) 3.0 (2006):

egest
    v 1: eliminate from the body; "Pass a kidney stone" [syn:
         excrete, egest, eliminate, pass]