War  —n. 1 a armed hostilities between esp. Nations; conflict. B specific instance or period of this. C suspension of international law etc. During this. 2 hostility or contention between people, groups, etc. 3 (often foll. By on) sustained campaign against crime, poverty, etc. —v. (-rr-) 1 (as warring adj.) Rival; fighting. 2 make war.  at war (often foll. By with) engaged in a war. Go to war declare or begin a war.