militante

militante: activist; fighter

On Friday Democracy Now! covered President Carter calling Cheney a militant. Webster's has a militant listed first as someone who engages in warfare, and second as someone who is combative for their cause. I assume Carter meant the first, and I think it's far and away the stronger association for that term in English, so I often flinch when I hear interps going into En render militante with its cognate - because usually in our contexts the Sp speakers are not talking about being guerilla fighters, and in fact very much do not want to be seen that way (no joke in Colombia where you can be killed for a rumor like that). Usually it seems to me that "activist" is the more appropriate cultural equivalent. And then there are those times when your speaker will say "yo era militante con el Frente" (though really, they'd usually say "yo militaba") and there you go by context. I still wouldn't use militant though. I'd say "I was a fighter with" or "I fought with".