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Definition of fiendish

fiendish

/ˈfiːn.dɪʃ/
fien · dish
Adverb:fiendishly
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fiendish Lexical Profile

fiendish Game Scores & Validity

• adjective

1

Extremely cruel, wicked, or malicious; characteristic of a fiend or demon.

Example

"The novel's antagonist devised a fiendish plot to ruin his rival's reputation."

2

Extremely complex, clever, or difficult to solve or overcome.

Example

"The Sunday newspaper featured a fiendish crossword puzzle that stumped everyone in the office."

Synonyms
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Antonyms
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• Nearby Words

fieldwork
fieldworker
fiend
fiendish
fiendishly
fierce
fierce snake

Word Origin & Etymology

Formed in Middle English from 'fiend' (from Old English 'feond', meaning an enemy, adversary, or devil) and the adjectival suffix '-ish'.

Cite this Entry

Wordmom. (2026). Definition of Fiendish. In Wordmom Dictionary. Retrieved Nov 5, 2026, from https://wordmom.com/dictionary/fiendish
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