A person who instigates or stirs up conflict, rebellion, or unrest; one who incites trouble.
From Latin 'fomentare' (to incite) plus the agent suffix '-er' (one who does). First recorded in English in the 17th century.
The founding fathers worried obsessively about 'rioters' and 'fomenters'—they understood that you don't need a majority to cause chaos, just someone charismatic enough to add heat to existing anger.
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