ferment

UK: verb: /fə^rˈmɛnt/, noun: /ˈfɜː^rmɛnt/

US: /n. ˈfɝmɛnt; v. fɚˈmɛnt/

US: (n.  fûr′ment; v. fər ment′)

WordReference Random House Learner's Dictionary of American English © 2025

fer•ment /n. ˈfɜrmɛnt; v. fɚˈmɛnt/   n. [uncountable]

1. agitation or excitement;
   commotion:
   political ferment.

v. 

2. to (cause to) undergo fermentation: [no object]
   When wine ferments, it changes sugar to alcohol.
   [~ + object]
   This enzyme ferments the wine faster.

WordReference Random House Unabridged Dictionary of American English © 2025

fer•ment  (n.  fûr′ment;v. fər ment′), n. 

1. Biochemistry Also called organized ferment. any of a group of living organisms, as yeasts, molds, and certain bacteria, that cause fermentation.
2. Ecology Also called unorganized ferment. an enzyme.
3. fermentation.
4. agitation;
   unrest;
   excitement;
   commotion;
   tumult:
   The new painters worked in a creative ferment. The capital lived in a political ferment.

v.t. 

5. to act upon as a ferment.
6. to cause to undergo fermentation.
7. to inflame;
   foment:
   to ferment prejudiced crowds to riot.
8. to cause agitation or excitement in:
   Reading fermented his active imagination.

v.i. 

9. to be fermented;
   undergo fermentation.
10. to seethe with agitation or excitement.

• Latin fermentum yeast (noun, nominal), fermentāre to cause to rise (verb, verbal); akin to barm, Latin fervēre to boil
• Middle English 1350–1400

fer•ment′a•ble, adj. 
fer•ment′a•bil′i•ty, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

ferment noun / ˈfɜːmɛnt/

1. any agent or substance, such as a bacterium, mould, yeast, or enzyme, that causes fermentation
2. another word for fermentation
3. commotion; unrest

verb / fəˈmɛnt/

1. to undergo or cause to undergo fermentation
2. to stir up or seethe with excitement

Etymology: 15th Century: from Latin fermentum yeast, from fervēre to seethe

ferˈmentable adjective

USAGE
foment