-dish, -dēsh adjective
1. : perversely diabolical : hideous
a fiendish pleasure in hurting people
2. : extremely cruel or wicked
a fiendish old man
3. : excessively bad, unpleasant, or difficult
fiendish weather
a fiendish punishment
• fiend·ish·ly adverb
• fiend·ish·ness noun -es