Source : Webster's Revised Unabridged Dictionary (1913)

Lithophagous \Li*thoph"a*gous\, a. [Litho- + Gr. ? to eat.]
   (Zo["o]l.)
   (a) Eating or swallowing stones or gravel, as the ostrich.
   (b) Eating or destroying stone; -- applied to various animals
       which make burrows in stone, as many bivalve mollusks,
       certain sponges, annelids, and sea urchins. See
       {Lithodomus}.