HELLACIOUS Synonyms: 154 Similar and Opposite Words

hellacious

adjective

ˌhe-ˈlā-shəs

Definition of hellacious

as in intense

extreme in degree, power, or effect the hellacious heat was more than we could bear

Synonyms & Similar Words

Relevance

Antonyms & Near Antonyms

as in difficult

requiring considerable physical or mental effort the pioneers survived a particularly hellacious river crossing with their covered wagon barely in one piece

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 hellacious His hellacious brand of defense is a nightmare for opposing benches in particular. — Bryan Toporek, Forbes.com, 18 May 2026 The skiers were in a valley below Perry Peak, but the two survivors have described battling through hellacious conditions in the hour before the avalanche. — Andrew Graham april 2, Sacbee.com, 2 Apr. 2026 But the tour was a hellacious time for Bachman. — Andy Greene, Rolling Stone, 28 Feb. 2026 Even against a hellacious Houston defense, the Patriots’ shortest path to victory is to ask Maye to carry them yet again. — Andrew Callahan, Boston Herald, 15 Jan. 2026 See All Example Sentences for hellacious

Recent Examples of Synonyms for hellacious

Adjective

Broadly, the rule of thumb is to drink it during periods of intense competition (to allow for muscle recovery) while avoiding it during periods of training (to promote muscle development).

— Jacob Whitehead, New York Times, 8 Sep. 2026
Expect Missouri to come out sharper and fired up, as both teams will be for this intense rivalry.

— PJ Green September 8, Kansas City Star, 8 Sep. 2026

Definition of intense

Adjective

Being undefeated after a trio of difficult opening matches can only be seen as a positive, even if Newcastle’s obvious shortcomings require addressing if that run is to be prolonged.

— Chris Waugh, New York Times, 6 Sep. 2026
Engineers need flight data on propulsion, aerodynamics, thermal management, guidance and other subsystems under conditions that are difficult to reproduce on the ground.

— Bojan Stojkovski, Interesting Engineering, 6 Sep. 2026

Definition of difficult

Adjective

The result should be better performance at the chip's limits, for graphics-intensive apps and games, and for extended multitasking.

— Brian Westover, PC Magazine, 10 Sep. 2026
Researchers can use it to run complex simulations, analyze large datasets, and develop compute-intensive AI applications.

— Kaif Shaikh, Interesting Engineering, 9 Sep. 2026

Definition of intensive

Adjective

Eric Loucks, the director of the Mindfulness Center at Brown, pointed out that a person can have a challenging experience during meditation and still find their overall meditation practice to be beneficial.

— Olga Khazan, The Atlantic, 4 Sep. 2026
For something more hands-on, Atlanta Motorsports Park in Dawsonville has a challenging kart circuit where karts can reach 50 mph or more.

— Chris Teague, AJC.com, 4 Sep. 2026

Definition of challenging

Adjective

Warren Buffett’s Berkshire Hathaway owns BNSF, and the railroad is a fierce critic of Vena’s takeover bid for Norfolk Southern.

— John Lippert, Chicago Tribune, 6 Sep. 2026
Aaron Donald, one of the fiercest pass rushers in NFL history, is coming out of retirement to rejoin the Rams in hopes of winning another Super Bowl title.

— Los Angeles Times, Los Angeles Times, 6 Sep. 2026

Definition of fierce

Adjective

Competing in a Grand Tour is one of sport’s toughest endurance tests.

— Chris Marshall-Bell, New York Times, 11 Sep. 2026
Trump used several minutes of his speech to praise Republican Texas Attorney General Ken Paxton, who is in a tough Senate race in America's largest red state.

— Arkansas Online, Arkansas Online, 10 Sep. 2026

Definition of tough

Adjective

Giamatti makes Jerry ferocious but not monstruous, a man who certainly likes barking orders at various underlings but loves making good theater even more.

— Angie Han, HollywoodReporter, 6 Sep. 2026
Up to this point, Ghostface victims have been stabbed with Buck 120 hunting knives, crushed by garage doors, shot, electrocuted, and thrown off rooftops in ferocious, balls-to-the-wall Scream fashion.

— Michael Lee Simpson, Entertainment Weekly, 5 Sep. 2026

Definition of ferocious

Adjective

Popularists, such as the data scientist David Shor and the writer Matt Yglesias, have advocated using rigorous polling and analytics to develop a Democratic agenda that appeals to the median voter.

— Jason Zengerle, New Yorker, 10 Sep. 2026
That’s led to more rigorous testing and higher standards, including a set of rules by the American Petroleum Institute that took effect at the start of the decade.

— Adam Ismail, The Drive, 10 Sep. 2026

Definition of rigorous

Browse Nearby Words

hell

hellacious

hell-bent

See all Nearby Words

Cite this Entry

Style

“Hellacious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/hellacious. Accessed 12 Sep. 2026.

Copy Citation

Synonyms of hellacious

adjective

Example Sentences

Browse Nearby Words

Cite this Entry

More from Merriam-Webster

Word of the Day

hobnob

Popular in Grammar & Usage

Merriam-Webster’s Great Big List of Words You Love to Hate

A Who’s Who Regarding ‘Who’s’ and ‘Whose’

Why do we use apostrophes to show possession?

Is it 'nerve-racking' or 'nerve-wracking'?

What's the difference between 'fascism' and 'socialism'?

Popular in Wordplay

9 Words That Sound Like Insults But Aren't

Back to School Vocabulary

Words from the 'Odyssey'

Ye Olde Nincompoop: Old-Fashioned Words for 'Stupid'

14 Phobias You Probably Haven't Heard Of

Popular

Merriam-Webster’s Great Big List of Words You Love to Hate

9 Words That Sound Like Insults But Aren't

Back to School Vocabulary

Games & Quizzes