ululate vs yell

ululate is not a noun while yell is a noun.

Word	Noun	Adjective	Verb	Adverb
ululate	No	No	Yes	No
yell	Yes	No	Yes	No

As verbs, yell is a hypernym of ululate; that is, yell is a word with a broader meaning than ululate:

Other hypernyms of ululate include call, cry, holler, hollo, scream, shout, shout out, squall.

ululate (noun)	yell (noun)
	a loud utterance; often in protest or opposition
	a loud utterance of emotion (especially when inarticulate)

ululate (verb)	yell (verb)
emit long loud cries	utter or declare in a very loud voice
	utter a sudden loud cry