shrill vs hollo

shrill is not a noun while hollo is a noun.

Word	Noun	Adjective	Verb	Adverb
shrill	No	Yes	Yes	No
hollo	Yes	No	Yes	No

As verbs, hollo is a hypernym of shrill; that is, hollo is a word with a broader meaning than shrill:

Other hypernyms of shrill include call, cry, holler, scream, shout, shout out, squall, yell.

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

shrill (adjective)	hollo (adjective)
of colors that are bright and gaudy
having or emitting a high-pitched and sharp tone or tones
being sharply insistent on being heard

shrill (verb)	hollo (verb)
utter a shrill cry	utter a sudden loud cry
	cry hollo
	encourage somebody by crying hollo