RENIN Meaning of RENIN in English /ree"nin/ , n. Biochem.a proteolytic enzyme secreted by the kidneys that is involved in the release of angiotensin. [ 1890-95; REN(I)- + -IN 2 ] Random House Webster's Unabridged English dictionary. Полный английский словарь Вебстер - Random House . 2012