slogan, rallying cry, call to arms, rally, watchword, battle cry, rebel yell, war whoop*; see also cheer 3.
"war cry." YourDictionary, n.d. Web. 19 August 2018. <http://thesaurus.yourdictionary.com/war-cry>.
war cry. (n.d.). Retrieved August 19th, 2018, from http://thesaurus.yourdictionary.com/war-cry
A rallying term used by proponents of a cause: