fiendish

[feen-dish]

adjective

1. diabolically cruel and wicked.

fiendish

/ ˈfiːndɪʃ /

adjective

1. of or like a fiend

2. diabolically wicked or cruel

3. informal,  extremely difficult or unpleasant

   a fiendish problem

Other Word Forms

• fiendishly adverb
• fiendishness noun

Word History and Origins

Origin of fiendish¹

First recorded in 1520–30; fiend + -ish ¹

Example Sentences

But drawing players away from multiplayer behemoths like Fortnite and Call of Duty has proved, for others at least, to be a challenge more fiendish than even FromSoftware could dream up.

From BBC

Ritter’s second novel is a fiendish tale of trouble in paradise.

From Los Angeles Times

Jumbo brings a humanizing clarity to Lady Macbeth without in the least compromising her character’s fiendish side.

From Los Angeles Times

The only advice Ms Keast-Butler gave BBC Breakfast earlier on Wednesday was to work in a team and "bring a rich mix of minds" to the fiendish puzzle.

From BBC

In these scenes, it’s hard to take your eyes off the glinting McAvoy, who’s like some fiendish juggler of items both benign and dangerous.

From Los Angeles Times

Related Words

• brutish 
• nefarious