Definitions

1. adjective

extremely wicked or evil; delighting in or characterized by evil or cruelty.

“The villain’s diabolical plan to take over the city was uncovered by the detectives.”

2. noun

a wicked or evil person or thing.

“The diabolical villain was finally brought to justice.”

3. adverb

in a wicked or evil manner.

“The new movie was diabolically intense and thrilling.”