There are multiple definitions - click on the translation that matches your context.

wojujący, gwałtowny, bojowy, wojowniczy, walczący

przymiotnik

full

militant

adjective

Definitions of militant

willing to use determined methods, often including confrontation, force, or violence, to support a particular cause

Ms Burnett was head of the militant group, the Wincheap Revolutionary Separatist Front.