the membrane lining the stomach of a young calf or related animal, or a prepared extract from this, used for curdling milk
the membrane lining the stomach, esp the fourth stomach, of a young calf or related animal, used for curdling milk
a prepared extract from the stomach or stomach lining of a young animal, that contains the enzyme rennin and is used for curdling milk to make cheese and junket
any preparation containing rennin or a substance having the action of rennin on milk
[prob from an Old English word related to run1]