devilish vs diabolical

devilish and diabolical both are adjectives.

Word	Noun	Adjective	Verb	Adverb
devilish	No	Yes	No	Yes
diabolical	No	Yes	No	No

As adjectives, devilish and diabolical are synonyms defined as:

devilish and diabolical: showing the cunning or ingenuity or wickedness typical of a devil

Other synonyms of devilish include diabolic, mephistophelean, mephistophelian.

devilish (adjective)	diabolical (adjective)
showing the cunning or ingenuity or wickedness typical of a devil	extremely evil or cruel; expressive of cruelty or befitting hell
playful in an appealingly bold way	showing the cunning or ingenuity or wickedness typical of a devil

devilish (adverb)	diabolical (adverb)
in a playfully devilish manner