agitator
noun /ˈædʒɪteɪtə(r)/
  /ˈædʒɪteɪtər/
 (disapproving)- a person who tries to persuade people to take part in political protest(政治上的)煽动者,鼓动者 - a known agitator and troublemaker众所周知的煽动者和麻烦制造者 
 词源mid 17th cent. (denoting a delegate of private soldiers in the Parliamentary army during the English Civil War): from Latin, from agitare, frequentative of agere ‘do, drive’. The current sense dates from the mid 18th cent.
- a known agitator and troublemaker