Fermentation

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.

A state of agitation or excitement, as of the intellect or the feelings.

a process in which an agent causes an organic substance to break down into simpler substances; especially, the anaerobic breakdown of sugar into alcohol