After their defeat in battle, the soldiers surrendered.

defeat 是动词 defeat 的名词形式，意思是"失败、战败"。动词 defeat 表示"击败、战胜"的意思，名词 defeat 则表示"被击败的状态或结果"。 在军事语境中，defeat 特指"战败"，即军队在战斗中被对方击败的情况。