1. aggressively active in supporting a cause or belief, often using confrontational methods
2. engaged in warfare or combat
Usage: formal

1. a person who is aggressively active in supporting a cause, especially a political cause

Examples

• The militant protesters blocked traffic to draw attention to their cause.
• She took a militant stance against corporate pollution.
• The militant group organized several demonstrations this month.
• His militant approach to reform alienated potential supporters.
• The militants demanded immediate policy changes.
• The union adopted militant tactics during the strike.
• Her militant activism earned both praise and criticism.