from
The Collaborative International Dictionary of English v.0.48
Rennet \Ren"net\, n. [AS. rinnan, rennan, to run, cf. gerinnan
to curdle, coagulate. [root]11. See {Run}, v.]
1. The inner, or mucous, membrane of the fourth stomach of
the calf, or other young ruminant.
[1913 Webster]
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}.]
[1913 Webster +PJC]
{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.
[1913 Webster +PJC]