Wiktionary
free-fire
a. Designating an area in which military personnel have authority to shoot on anyone without obtaining prior clearance.
Usage examples of "free-fire".
The recent mass strategy of antitobacco and teen smoking needs to be focused on our children before another school becomes a free-fire killing zone.
Second Fleet had declared a one hundred nautical mile free-fire zone around Task Force Twenty-One to give ample coverage against the fifty-mile range of the late-model Exocet ASMs of the Argentine Navy.