fiendish
adj/ˈfiːndɪʃ/
Etymology From fiend + -ish.
1
Sinister; evil; like a fiend.
- The detective was puzzled by the fiendish plot to steal the diamonds.
- She had a fiendish smile that hinted at a cunning plan.
2
Very difficult.
- The exam was filled with fiendish questions that made no sense.
- a fiendish crossword puzzle
- Derived terms
- fiendishly, fiendishness