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

• 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

Playing a school driver who has to get a bunch of kids to safety during a hellacious, out-of-control California fire, McConaughey learned how to drive a bus, grinding gears and everything. —Brian Truitt, USA Today, 19 Sep. 2025

The film bluntly communicates the danger of football on the body and brain, with X-ray-vision scenes that show players’ skeletons bearing the impact of hellacious hits. —Andre Gee, Rolling Stone, 18 Sep. 2025

Even in the hellacious conditions of Greater Los Angeles, the suspension absorbs severe potholes, broken surfaces and expansion joints with little more than the sound of a muffled timpani strike. —Mark Ewing, Forbes.com, 2 Aug. 2025

The other nailed two runners on the bases with some of the most hellacious throws anyone had ever seen. —Tyler Kepner, New York Times, 11 July 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