fermentation, ferment

fermentation: 2. Unrest; agitation.

ferment (as a verb): 

v.tr.

1. To produce by or as if by fermentation.

2. To cause to undergo fermentation.

3. To make turbulent; excite or agitate.

v.intr.

1. To undergo fermentation.

2. To be in an excited or agitated state; seethe.

... Am-Heritage