fer·ment • v. / fərˈment/ 1. [intr.] (of a substance) undergo fermentation. ∎  [tr.] cause the fermentation of (a substance).2. [tr.] incite or stir up (trouble or disorder): the politicians and warlords who are fermenting this chaos. ∎  [intr.] (of a negative feeling or memory) fester and develop into something worse: it had been fermenting in my subconscious for a while.• n. / ˈfərˌment/ 1. agitation and excitement among a group of people, typically concerning major change and leading to trouble or violence: Germany at this time was in a state of religious ferment.2. archaic a fermenting agent or enzyme.DERIVATIVES: fer·ment·a·ble adj.

ferment As a noun, the old name for enzyme. As a verb, to carry out the process of fermentation.

ferment leaven; fermentation (lit. and fig.). XV. — (O)F. ferment or L. fermentum, f. fervēre boil.
So vb. XIV. fermentation XIV. — late L.

Ferment

a tumult of agitation; an assembly of people affected by such a tumult, 1672.