fiendish

/ˈfindɪʃ/
adjective
  1. Extremely cruel or evil.
    • The villain had a fiendish plan to destroy the city.
    • The prisoners suffered under the fiendish guards.
    • Her fiendish laughter sent chills down everyone's spine.
  2. Very clever in a tricky or unpleasant way.
    • The maze had a fiendish design that confused everyone.
    • The puzzle was fiendish and took me hours to solve.
    • He came up with a fiendish scheme to cheat on the test.
  3. Extremely difficult or challenging.
    • Climbing that mountain in winter is a fiendish task.
    • She set a fiendish pace during the marathon.
    • The final exam was fiendish; hardly anyone passed.
Antonyms