"War" or "hero" prefix (4)

I believe the answer is:

anti

(Other definitions for anti that I've seen before include "Negative vote" , "Definitely not pro" , "Not favouring" , "[NO MAN]" , "An opponent - opposed to party policy, etc" .)

I've seen this clue in The Washington Post.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.