Source : Webster's Revised Unabridged Dictionary (1913)

Renal \Re"nal\ (r?"nal), a. [L. renalis, fr. renes the kidneys
   or reins: cf. F. r['e]nal. See {Reins}.] (Anat.)
   Of or pertaining to the kidneys; in the region of the
   kidneys.

   {Renal calculus} (Med.), a concretion formed in the excretory
      passages of the kidney.

Source : WordNet®

renal
     adj : of or relating to the kidneys [syn: {nephritic}]