What is "cheese rennet"

Rennet \Ren"net\, n. [AS. rinnan, rennan, to run, cf. gerinnan to curdle, coagulate. [root]1

1. See Run, v.] 1. The inner, or mucous, membrane of the fourth stomach of the calf, or other young ruminant.

2. an infusion or preparation of the calf stomach lining, used for coagulating milk. The active principle in this coagulating action is the enzyme rennin. [Written also runnet.]

   Cheese rennet. (Bot.) See under Cheese.

   Rennet ferment (Physiol. Chem.), the enzyme rennin, present in rennet and in variable quantity in the gastric juice of most animals, which has the power of curdling milk. The enzyme presumably acts by changing the casein of milk from a soluble to an insoluble form.

   Rennet stomach (Anat.), the fourth stomach, or abomasum, of ruminants.

Cheese \Cheese\ (ch[=e]z), n. [OE. chese, AS. c[=e]se, fr. L. caseus, LL. casius. Cf. Casein.]

1. The curd of milk, coagulated usually with rennet, separated from the whey, and pressed into a solid mass in a hoop or mold.

2. A mass of pomace, or ground apples, pressed together in the form of a cheese.

3. The flat, circular, mucilaginous fruit of the dwarf mallow ( Malva rotundifolia). [Colloq.]

4. A low courtesy; -- so called on account of the cheese form assumed by a woman's dress when she stoops after extending the skirts by a rapid gyration.
   --De Quincey.
   --Thackeray.

   Cheese cake, a cake made of or filled with, a composition of soft curds, sugar, and butter.
   --Prior.

   Cheese fly (Zo["o]l.), a black dipterous insect ( Piophila casei) of which the larv[ae] or maggots, called skippers or hoppers, live in cheese.

   Cheese mite (Zo["o]l.), a minute mite ( Tryoglyhus siro) in cheese and other articles of food.

   Cheese press, a press used in making cheese, to separate the whey from the curd, and to press the curd into a mold.

   Cheese rennet (Bot.), a plant of the Madder family ( Golium verum, or yellow bedstraw), sometimes used to coagulate milk. The roots are used as a substitute for madder.

   Cheese vat, a vat or tub in which the curd is formed and cut or broken, in cheese making.