hilarious vs screaming

hilarious is not a noun while screaming is a noun.

Word	Noun	Adjective	Verb	Adverb
hilarious	No	Yes	No	No
screaming	Yes	Yes	No	No

As adjectives, hilarious and screaming are synonyms defined as:

hilarious and screaming: marked by or causing boisterous merriment or convulsive laughter

Other synonyms of hilarious include uproarious.

hilarious (noun)	screaming (noun)
	sharp piercing cry
	a high-pitched noise resembling a human cry

hilarious (adjective)	screaming (adjective)
marked by or causing boisterous merriment or convulsive laughter	marked by or causing boisterous merriment or convulsive laughter
	so extremely intense as to evoke screams
	resembling a scream in effect