diabolic vs hellish

diabolic and hellish both are adjectives.

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

As adjectives, diabolic and hellish are synonyms defined as:

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

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

diabolic (adjective)	hellish (adjective)
extremely evil or cruel; expressive of cruelty or befitting hell	extremely evil or cruel; expressive of cruelty or befitting hell
showing the cunning or ingenuity or wickedness typical of a devil	(informal) very unpleasant