agitator
noun [ C ] uk/ˈædʒ.ɪ.teɪ.tər/ us/ˈædʒ.ə.teɪ.t̬ɚ/
disapproving（抗议或政治波动中的）煽动者，策动者
someone who tries to make people take part in protests and political activities, especially ones that cause trouble
It is thought that the strike was the work of undercover political agitators. 人们认为罢工背后有秘密政治势力在煽风点火。