rennet definition by Webster's New World
- the membrane lining the stomach of an unweaned animal, esp. the fourth stomach of a calf
- the contents of such a stomach
- an extract of this membrane or of the stomach contents, containing rennin and used to curdle milk, as in making cheese or junket
- any substance used to curdle milk
Origin: Middle English rennen, to cause to coagulate ; from Old English gerennan ; from ge-, together (see co-) plush Germanic an unverified form rannjan, to cause to run ; from base of an unverified form rinnan (from source run) plush an unverified form -jan, causative suffix
rennet definition by American Heritage Dictionary
- The inner lining of the fourth stomach of calves and other young ruminants.
- A dried extract made from the stomach lining of a ruminant, used in cheesemaking to curdle milk.
- See rennin.
Origin: Middle English, probably from Old English *rynet; see rei- in Indo-European roots.