Emily Dickinson Lexicon

REN'NET, n. [G. rinnen, to run, to curdle; D. runnen, ronnen, to curdle or coagulate; Sax. gerunnen, coagulated.]

The dried stomach or concreted milk found in the stomach of a sucking quadruped, particularly of the calf. It is also written Runnet, and this is the preferable orthography. – Encyc.