ferment in WordNet English dictionary

1. a state of agitation or turbulent change or development
   "the political ferment produced new leadership"; "social unrest"
   agitation  ferment  fermentation  tempestuousness  unrest 
   
2. a process in which an agent causes an organic substance to break down into simpler substances; especially, the anaerobic breakdown of sugar into alcohol
   zymosis  zymolysis  fermentation  fermenting  ferment 
   
3. a substance capable of bringing about fermentation
   ferment 
   

1. go sour or spoil
   "The milk has soured"; "The wine worked"; "The cream has turned--we have to throw it out"
   sour  turn  ferment  work 
   
2. cause to undergo fermentation
   "We ferment the grapes for a very long time to achieve high alcohol content"; "The vintner worked the wine in big oak vats"
   ferment  work 
   
3. work up into agitation or excitement
   "Islam is fermenting Africa"
   ferment 
   
4. be in an agitated or excited state
   "The Middle East is fermenting"; "Her mind ferments"
   ferment