1 [U] [C] a state of fighting between different countries or groups within countries using armies and weapons 战争（状态）: The Prime Minister announced that the country was at war. 首相宣布国家处于战争状态。to declare war onanother country (= announce that a war has started) 向另一国宣战When war broke out (= started), thousands of men volunteered for the army. 战争爆发，数以千计的人自愿参军。a civil war(= fighting between different groups in one country) 内战to go to waragainst sb 与某人开战to fight a war 打一场战争

2 [C,U] very aggressive competition between groups of people, companies, countries, etc （人际、公司、国家等间的）激烈竞争: a price war among oil companies 石油公司的价格战

3 [U] [sing] war (against/on sb/sth) efforts to end or get rid of sth 消灭或摆脱…的行动: We seem to be winning the war against organized crime. 我们看来正赢得这场打击有组织犯罪的斗争。