hellacious

adjective

hel·​la·​cious ˌhe-ˈlā-shəs 

1

: exceptionally powerful or violent

hellacious winds

2

: remarkably good

has a hellacious curve ball

3

: extremely difficult

a hellacious climb

4

: extraordinarily large

a hellacious traffic jam

hellaciously adverb

Synonyms of hellacious

• intense
• intensive
• fierce
• ferocious
• terrible
• deep
• furious
• heavy

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

This was a hellacious heavyweight matchup that lived up to the hype. —Scott Wheeler, New York Times, 10 Apr. 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

Edmonton superstar Connor McDavid dished out three assists and a hellacious hit on Czechia forward Lukas Sedlec on his first shift early in the first period that set the tone for a fast paced, hard hitting and unselfish display of often breathtaking hockey. —Scott M. Reid, Oc Register, 13 Feb. 2026

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