Definition of fiendish
1 : perversely diabolical took a fiendish pleasure in hurting people
2 : extremely cruel or wicked
3 : excessively bad, unpleasant, or difficult fiendish weather
Examples of fiendish in a sentence
He takes a fiendish delight in hurting people.
a fiendish delight in playing cruel tricks
First Known Use of fiendish
FIENDISH Defined for English Language Learners
Definition of fiendish for English Language Learners
: very evil or cruel
: extremely bad, unpleasant, or difficult
Seen and Heard
What made you want to look up fiendish? Please tell us where you read or heard it (including the quote, if possible).