Jacobin

n. [Fr. Jacobin;—so named from the place of meeting, which was the monastery of the monks called Jacobines.] (Hist.) One of a society of violent revolutionists in France, during the revolution of 1789, who held secret meetings, in which measures were concerted to direct the proceedings of the National Assembly. Hence, any one who opposes government in a secret and unlawful manner, or by factious methods; a turbulent demagogue.