bellowing vs yell

bellowing and yell both are nouns.

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

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

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

bellowing (noun)	yell (noun)
a very loud utterance (like the sound of an animal)	a loud utterance; often in protest or opposition
	a loud utterance of emotion (especially when inarticulate)

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