FIENDISH Synonyms: 107 Similar and Opposite Words

fiendish

adjective

ˈfēn-dish

Definition of fiendish

as in demonic

of, relating to, or worthy of an evil spirit a fiendish delight in playing cruel tricks

Synonyms & Similar Words

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Antonyms & Near Antonyms

as in brutal

having or showing the desire to inflict severe pain and suffering on others shook with fiendish laughter as he watched his victims writhe in agony

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Antonyms & Near Antonyms

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

Recent Examples of fiendish Plotting kind of my most fiendish, happy, mad scientist state. — Literary Hub, 4 May 2026 The soloist in the Sibelius was a mediocre violinist ill-equipped to deal with the concerto’s profound emotions and fiendish technical demands. — Luis Palomares, Miami Herald, 27 Feb. 2026 Jim Carrey plays the eponymous Grinch, a fiendish Whoville outlaw who declares war on the festive season. — Danny Horn, Entertainment Weekly, 29 Nov. 2025 Miller works with him to refine the routes, placing checkpoints that are both fair and fiendish. — New Atlas, 1 Nov. 2025 See All Example Sentences for fiendish

Recent Examples of Synonyms for fiendish

Adjective

Pane and McKay revealed that British actor Simon Pegg will voice the Balrog, a giant demonic monster who helps Sauron forge the One Ring.

— Laura Sirikul, Forbes.com, 27 July 2026
The godless ’60s had radicalized many Christians who saw the toxic stew of drugs, rock ’n’ roll, and shallow commercialism as a sign of the end times and vowed to reverse the demonic tide.

— Literary Hub, Literary Hub, 24 July 2026

Definition of demonic

Adjective

And, as the Punisher, Frank is known to enact particularly brutal, bloody vengeance.

— Angelique Jackson, Variety, 31 July 2026
After opening the season on the big-league roster and then suffering a demotion after a brutal debut, Phillies pitcher Andrew Painter could be poised to make a stunning return to the mound against the Orioles.

— Peter Chawaga, Forbes.com, 31 July 2026

Definition of brutal

Adjective

There was something so sinister about FIFA pushing the idea of diversity while bending the knee to a government working to discard the real thing.

— Olivier Lafontant, Pitchfork, 20 July 2026
Outside, the cops, led by a dry sinister officer in a long black leather coat, order him to get on the ground, face down; Sophia comes out of the house and is placed in the back of a car, staring at all this through the glass.

— Owen Gleiberman, Variety, 16 July 2026

Definition of sinister

Adjective

Gomez has endured a lengthy list of cruel setbacks during his 11-year Liverpool career and faces a wait to learn the extent of his latest injury.

— James Pearce, New York Times, 26 July 2026
Obsessed with recovering her fortune, Magdalen’s uses of disguise and performance become manipulative, treacherous, and even cruel.

— Literary Hub, Literary Hub, 24 July 2026

Definition of cruel

Adjective

When Ahab first speaks to the crew about Moby Dick, his diabolical charisma soon infects the men who, apart from Starbuck, enthusiastically join him in his monomaniacal crusade.

— Literary Hub, Literary Hub, 6 July 2026
From perhaps the most diabolical spot on the entire course.

— Brendan Quinn, New York Times, 20 June 2026

Definition of diabolical

Adjective

The drastic measures Alice takes to end this vicious cycle naturally bring her closer to Catherine’s school of violent retribution.

— Alison Herman, Variety, 27 July 2026
Despite the powerful action and vicious fight scenes the franchise is known for, Laufey is still shaping up as a bit of a love story.

— Brian Mazique, Forbes.com, 25 July 2026

Definition of vicious

Adjective

These errors can cause crashes or enable attackers to exploit memory vulnerabilities, risking data corruption or executing malicious code.

— Davey Winder, Forbes.com, 31 July 2026
Elijah Bieniemy, who is 27 and is a graduate of Olathe Northwest High School, has been charged with malicious wounding, use of a firearm during the commission of a felony and discharge of a firearm inside of a dwelling.

— Pete Grathoff, Kansas City Star, 31 July 2026

Definition of malicious

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fiendish

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“Fiendish.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/fiendish. Accessed 1 Aug. 2026.

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Synonyms of fiendish

adjective

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