hellacious

adjective

hel·​la·​cious ˌhe-ˈlā-shəs 

1

: exceptionally powerful or violent

2

: remarkably good

3

: extremely difficult

4

: extraordinarily large

hellaciously adverb

Synonyms

• acute
• almighty
• blistering
• deep
• dreadful
• excruciating
• explosive
• exquisite
• fearful
• fearsome
• ferocious
• fierce
• frightful
• furious
• ghastly
• hard
• heavy
• heavy-duty
• intense
• intensive
• keen
• profound
• terrible
• vehement
• vicious
• violent

Examples of hellacious in a Sentence

Traffic is hellacious this time of day.

the hellacious heat was more than we could bear

Recent Examples on the Web

There were several hellacious spots, but the final blow was a concerto from Priest. —Brian Mazique, Forbes.com, 25 May 2025

After a solid start, his defensive flaws and diminished reflexes left him open for a hellacious left hook from Rodriguez. —Brian Mazique, Forbes.com, 4 May 2025

Scott’s hellacious run in hip-hop can be credited to his 100-plus Billboard Hot 100 entries and two blockbuster releases, 2018’s Astroworld and 2023’s Utopia, which both secured the top spot on the Billboard 200. —Carl Lamarre, Billboard, 3 Sep. 2019

The canine snarl and hellacious production of Whole Lotta Red has dissipated for something sleeker, more vaporous. —Olivier Lafontant, Pitchfork, 8 Jan. 2025

Word History

Etymology

hell + -acious (as in audacious)

First Known Use

1929, in the meaning defined at sense 1

Rhymes for hellacious

• arenaceous
• argillaceous
• carbonaceous
• contumacious
• coriaceous
• efficacious
• farinaceous
• foliaceous
• membranaceous
• ochraceous
• olivaceous
• ostentatious