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: Webster's Revised Unabridged Dictionary (1913)