Source : Webster's Revised Unabridged Dictionary (1913)

Alfet \Al"fet\, n. [LL. alfetum, fr. AS. [=a]lf[ae]t a pot to
   boil in; [=a]l burning + f[ae]t vat.]
   A caldron of boiling water into which an accused person
   plunged his forearm as a test of innocence or guilt.