Source : Webster's Revised Unabridged Dictionary (1913)

Viscus \Vis"cus\, n.; pl. {Viscera}. [L., perhaps akin to E.
   viscid.] (Anat.)
   One of the organs, as the brain, heart, or stomach, in the
   great cavities of the body of an animal; -- especially used
   in the plural, and applied to the organs contained in the
   abdomen.

Source : WordNet®

viscus
     n : a main organ that is situated inside the body [syn: {internal
         organ}]