Source : Webster's Revised Unabridged Dictionary (1913)

Lithology \Li*thol"o*gy\, n. [Litho- + -logy: cf. F.
   lithologie.]
   1. The science which treats of rocks, as regards their
      mineral constitution and classification, and their mode of
      occurrence in nature.

   2. (Med.) A treatise on stones found in the body.