battle 侧重指战争中的一次较全面、时间较长的战斗，也指陆军或海军在某一特定地区进行的战斗，或个人之间的争斗。
war 是战争的总称，一般指包括多个战役的大规模战争。
campaign 通常指在一场大的战争中在某一地区进行的一连串有既定目的的军事行动。也可作引申用。
struggle 指激烈或时间持续长的战斗或奋力斗争。
war fare侧重指战争状态或具体的作战方法。
fight 最普通用词，含义广，指战斗、斗争或打斗。
combat 泛指军事行动，尤指小规模的战斗，甚至是格斗。
engagement 指交战，交火。
参考例句
1. They were fighting in order to preserve their independence. 他们为了维护他们的独立而斗争
2. We train for war and fight to win. 我们为战争而训练、为胜利而作战。
3. We know how to work, to sacrifice, and to fight. 我们懂得如何去工作，去战斗，去作出牺牲。
英英解释
n.
1. the act of fighting; any contest or struggle
2. an intense verbal dispute
3. a boxing or wrestling match
4. a hostile meeting of opposing military forces in the course of a war
5. an aggressive willingness to compete v.
1. be engaged in a fight; carry on a fight
2. fight against or resist strongly
3. make a strenuous or labored effort
4. exert oneself continuously, vigorously, or obtrusively to gain an end or engage in a crusade for a c
