unholy vs hellish

unholy and hellish both are adjectives.

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

As adjectives, unholy and hellish are synonyms defined as:

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

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

unholy (adjective)	hellish (adjective)
not hallowed or consecrated	extremely evil or cruel; expressive of cruelty or befitting hell
extremely evil or cruel; expressive of cruelty or befitting hell	(informal) very unpleasant
having committed unrighteous acts