n. & v.
n. 1 agitation, excitement, tumult. 2 a fermenting, fermentation. b a fermenting-agent or leaven.
v. 1 intr. & tr. undergo or subject to fermentation. 2 intr. & tr. effervesce or cause to effervesce. 3 tr. excite; stir up; foment. fermentable adj. fermenter n.
[ ME f. OF ferment or L fermentum f. L fervere boil ]