battle cry
     n 1: a yell intended to rally a group of soldiers in battle [syn:
           {war cry}, {war whoop}, {rallying cry}]
     2: a slogan used to rally support for a cause; "a cry to arms";
        "our watchword will be `democracy'" [syn: {war cry}, {rallying
        cry}, {cry}, {watchword}]
Source: WordNet® 2.0