Source : Webster's Revised Unabridged Dictionary (1913)

Nephrology \Ne*phrol"o*gy\, n. [Gr. ? a kidney + -logy.]
   A treatise on, or the science which treats of, the kidneys,
   and their structure and functions.

Source : WordNet®

nephrology
     n : the branch of medicine concerned with the kidney - its
         development and anatomy and physiology and disorders