Entry 1 sense Webster, 1913 Renal /(rē"nal)/ · Re·nal · IPA /ˈɹi.nəl/ 01 a. Of or pertaining to the kidneys; in the region of the kidneys. 1. Of or pertaining to the kidneys; in the region of the kidneys.(Anat.) Phrases & compounds Renal capsules — the suprarenal capsules. See under Capsule. Renal casts — See under Cast, and Colic.