An entrenched or aggressive adherent to a particular cause, now especially a member of a particular ideological faction.
Specifically, someone who supports the Trotskyist political view expressed in the newspaper Militant, or who engages in aggressive left-wing politics.
Fighting or disposed to fight; belligerent, warlike.
Aggressively supporting of a political or social cause; adamant, combative.
A young person who agitates for political or other reform; a young person with a rebellious disposition.
From the late-19th to the early-20th century, a member of a movement that campaigned for reform of the Ottoman Empire.