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

Synonyms & Similar Words

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 Across the short films, Early plays, among other roles, a smiling, fiendish mall pop act; the shy, offbeat child of an overbearing stage mom; and an extra in a makeup chair whose instruments, his face and his voice, are progressively hampered by prosthetics. — Lauren Michele Jackson, New Yorker, 7 June 2026 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 See All Example Sentences for fiendish

Recent Examples of Synonyms for fiendish

Adjective

The Devil’s portrait is included as an acknowledgment of demonic assistance.

— Laura Payne, Encyclopedia Britannica, 30 Oct. 2026
Blaze/Ghost Rider did not exactly have a signature villain but did have a coterie of demonic antagonists.

— Aaron Couch, HollywoodReporter, 27 Oct. 2026

Definition of demonic

Adjective

In Samo’s warped reality, omnipresent hornets gain an evil power, forcing him to confront his mother in what could turn into a brutal showdown.

— Georg Szalai, HollywoodReporter, 30 Oct. 2026
At this point, both teams are just playing for bowl eligibility, with brutal November schedules awaiting each team.

— Steven Johnson, Fort Worth Star-Telegram, 30 Oct. 2026

Definition of brutal

Adjective

The Democrat’s disposition as a love-thy-trans-neighbor seminarian is a cover for something far more sinister, the argument goes.

— Aidan McLaughlin, Vanity Fair, 30 Oct. 2026
The sinister presence torments the family, and when their two-year-old suddenly vanishes, fear spirals into hysteria and paranoia as the family confronts a terrifying force that has turned their connected world against them.

— Melanie Goodfellow, Deadline, 29 Oct. 2026

Definition of sinister

Adjective

People talking to an AI in an abusive and cruel way are more likely to be associated with trying to get the AI model to engage in dangerous requests, like trying to get around an AI’s safety guardrails, Campbell added.

— Hadas Gold, CNN Money, 1 Nov. 2026
From the very start, the students assigned as guards went on cruel power trips and repeatedly humiliated — if not psychologically tortured — the inmates, to the point that some of the prisoners suffered nervous breakdowns.

— Frank Landymore, Futurism, 29 Oct. 2026

Definition of cruel

Adjective

Numerous treatise writers began to insist that anyone who doubts the diabolical empowerment of women-as-witches is self-deluded and dangerous.

— Literary Hub, Literary Hub, 14 Oct. 2026
Almost as soon as Jackie enters her flat there, she is accosted by gunmen, narrowly escaping before learning the diabolical and psychopathic mercenaries, The Seven Demons, have been tasked with ending her life.

— Aramide Tinubu, Variety, 2 Oct. 2026

Definition of diabolical

Adjective

For the moment, Trump’s vicious bigotry has alienated most independent voters and even some Republicans.

— David Yassky, New York Daily News, 2 Nov. 2026
Outside observers described his vicious consolidation of power as an attempt to compensate for his youth, his limited political experience, and his complete lack of a military background.

— Jieun Baek, Foreign Affairs, 30 Oct. 2026

Definition of vicious

Adjective

Reducing Gulliver’s Travels to only a topsy-turvy tale of humans both tiny and massive is to ignore the savage intellect that penned its words.

— Literary Hub, Literary Hub, 28 Oct. 2026
In ancient, supposedly more savage times, public killings were common.

— Dr. Michael Good, Hartford Courant, 22 Oct. 2026

Definition of savage

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fiendish

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“Fiendish.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/fiendish. Accessed 4 Nov. 2026.

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Synonyms of fiendish

adjective

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