Definition of "militant"

militant

/ˈmɪlɪtənt/

adjective
comparative more militant, superlative most militant
1. Fighting or disposed to fight; belligerent, warlike.
  Quotations
  The upper tiers of the foreign ministry were quick to embrace a militant policy.
  2012, Christopher Clark, The Sleepwalkers, Penguin, published 2013, page 394
2. Aggressively supporting of a political or social cause; adamant, combative.
noun
plural militants
1. (obsolete) A soldier, a combatant.
2. An entrenched or aggressive adherent to a particular cause, now especially a member of a particular ideological faction.
  Quotations
  Officials in Pakistan have confirmed that at least 250 schoolchildren between 12 and 18 years old and several teachers were taken hostage by at least seven militants inside a high school in Domail.
  2008, Militants in Pakistan release 250 schoolchildren after taking them hostage, Wikinews
3. (specifically, communism) someone who supports the Trotskyist political view expressed in the newspaper Militant, or who engages in aggressive left-wing politics.