noun (n)

• a state of agitation or turbulent change or development(noun.state)

  Synonym:
  agitation, ferment, tempestuousness, unrest
  

  source: wordnet30
• a process in which an agent causes an organic substance to break down into simpler substances; especially, the anaerobic breakdown of sugar into alcohol(noun.process)

  Synonym:
  ferment, fermenting, zymolysis, zymosis
  

  source: wordnet30
• The process of undergoing an effervescent change, as by the action of yeast; in a wider sense (Physiol. Chem.), the transformation of an organic substance into new compounds by the action of a ferment, either formed or unorganized. It differs in kind according to the nature of the ferment which causes it.(noun)

  source: webster1913