Source : Webster's Revised Unabridged Dictionary (1913)

Excretion \Ex*cre"tion\, n. [Cf. F. excr['e]tion.]
   1. The act of excreting.

            To promote secretion and excretion.   --Pereira.

   2. That which is excreted; excrement. --Bacon.

Source : WordNet®

excretion
     n 1: the bodily process of discharging waste matter [syn: {elimination},
           {evacuation}, {excreting}, {voiding}]
     2: waste matter (as urine or sweat but especially feces)
        discharged from the body [syn: {body waste}, {excreta}, {excrement},
         {excretory product}]