fermentation
Pronunciation: /fəːmɛnˈteɪʃ(ə)n/
noun
- 1the chemical breakdown of a substance by bacteria, yeasts, or other microorganisms, typically involving effervescence and the giving off of heat: the fermentation of organic matter by micro-organisms in the gut
- the fermentation process involved in the making of beers, wines, and spirits, in which sugars are converted to ethyl alcohol.

Origin:
late Middle English: from late Latin fermentatio(n-), from Latin fermentare 'to ferment' (see ferment)