call out vs hollo

call out is not a noun while hollo is a noun.

Word	Noun	Adjective	Verb	Adverb
call out	No	No	Yes	No
hollo	Yes	No	Yes	No

call out (noun)	hollo (noun)
	a very loud utterance (like the sound of an animal)

call out (verb)	hollo (verb)
call out loudly, as of names or numbers	utter a sudden loud cry
utter aloud; often with surprise, horror, or joy	cry hollo
challenge to a duel	encourage somebody by crying hollo