Meaning

noun the waging of armed conflict against an enemy

noun a legal state created by a declaration of war and ended by official declaration during which the international rules of war apply

noun an active struggle between competing entities

originInherited from Middle English werre, from Late Old English werre /wyrre (“armed conflict”), from Anglo-Norman and Old Northern French guerre /werre (compare modern French guerre), from Medieval Latin werra, from Frankish *werʀu (“confusion; quarrel”), from Proto-Indo-European *wers- (“to mix up, confuse, beat, thresh”). Gradually displaced native Old English beadu, hild, ġewinn, orleġe, wīġ, and…

Etymology from Wiktionary, CC BY-SA 3.0