at war

1. 1. A state of open, armed, often prolonged conflict carried on between nations, states, or parties.

   2. The period of such conflict.

   3. The techniques and procedures of war; military science.

   4. A condition of active antagonism or contention: a war of words; a price war.

   5. A concerted effort or campaign to combat or put an end to something considered injurious: the war against acid rain.

2. 1. A condition of active antagonism or contention: a war of words; a price war.

   2. A concerted effort or campaign to combat or put an end to something considered injurious: the war against acid rain.

1. To wage or carry on warfare.

2. To be in a state of hostility or rivalry; contend.

Word History: The chaos of war is reflected in the semantic history of the word war. War can be traced back to the Indo-European root *wers-, "to confuse, mix up." In the Germanic family of the Indo-European languages, this root gave rise to several words having to do with confusion or mixture of various kinds. One was the noun *werza-, "confusion," which in a later form *werra- was borrowed into Old French, probably from Frankish, a largely unrecorded Germanic language that contributed about 200 words to the vocabulary of Old French. From the Germanic stem came both the form werre in Old North French, the form borrowed into English in the 12th century, and guerre (the source of guerrilla) in the rest of the Old French-speaking area. Both forms meant "war." Meanwhile another form derived from the same Indo-European root had developed into a word denoting a more benign kind of mixture, Old High German wurst, meaning "sausage." Modern German Wurst was borrowed into English in the 19th century, first by itself (recorded in 1855) and then as part of the word liverwurst (1869), the liver being a translation of German Leber in Leberwurst.