rallying_cry
1. [ noun ] a slogan used to rally support for a cause
Synonyms: cry battle_cry watchword war_cry
Examples:

"a cry to arms" "our watchword will be `democracy'"

Related terms: motto
2. [ noun ] a yell intended to rally a group of soldiers in battle
Synonyms: battle_cry war_whoop war_cry
Related terms: cry
Similar spelling:   rallying_point