hellish vs demonic

hellish and demonic both are adjectives.

Word	Noun	Adjective	Verb	Adverb
hellish	No	Yes	No	No
demonic	No	Yes	No	No

As adjectives, hellish and demonic are synonyms defined as:

hellish and demonic: extremely evil or cruel; expressive of cruelty or befitting hell

Other synonyms of hellish include diabolic, diabolical, fiendish, infernal, satanic, unholy.

hellish (adjective)	demonic (adjective)
extremely evil or cruel; expressive of cruelty or befitting hell	extremely evil or cruel; expressive of cruelty or befitting hell
(informal) very unpleasant