Webster's Revised Unabridged Dictionary · 1913

Rennin

Rennin (ren"nin) , noun

(Biochemistry) A milk-clotting enzyme obtained from the true stomach (abomasum) of a suckling calf. Mol. wt. about 31,000. Also called chymosin, rennase, and abomasal enzyme. — [Merck Man. 11]