rallying cry vs yell

rallying cry and yell both are nouns.

Word	Noun	Adjective	Verb	Adverb
rallying cry	Yes	No	No	No
yell	Yes	No	Yes	No

As nouns, yell is a hypernym of rallying cry; that is, yell is a word with a broader meaning than rallying cry:

Other hypernyms of rallying cry include call, cry, outcry, shout, vociferation.

rallying cry (noun)	yell (noun)
a slogan used to rally support for a cause	a loud utterance; often in protest or opposition
a yell intended to rally a group of soldiers in battle	a loud utterance of emotion (especially when inarticulate)

rallying cry (verb)	yell (verb)
	utter or declare in a very loud voice
	utter a sudden loud cry