Renal

adj. pertaining to kidneys, of the kidneys

The kidneys are organs that filter wastes (such as urea) from the blood and excrete them, along with water, as urine. The medical field that studies the kidneys and diseases of the kidney is called nephrology. The prefix nephro- meaning kidney is from the Ancient Greek word nephros (νεφρός); the adjective renal meaning related to the kidney is from Latin rēnēs, meaning kidneys.
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Renal /re·nal/ pertaining to the kidney. re·nal adj. Of or in the region of the kidneys. Renal Relating to the kidney. [more]Renal - Community and Resources

Adjective
1. of or relating to the kidneys
(synonym) nephritic
(pertainym) kidney

adj. kidney, renal