battle cry
1. A shout or chant issued by soldiers, especially when charging into battle. Let the enemy hear our battle cry from miles away; let them fear us from afar.
2. A particular slogan, chant, or motto used by a group or its proponents to generate enthusiasm and support. "No New Taxes" has become the new congressional candidate's battle cry for this election. The stadium shook with the battle cry of the team's home fans.