Hellacious
Hellacious adjective - Requiring considerable physical or mental effort.
Usage example: the pioneers survived a particularly hellacious river crossing with their covered wagon barely in one piece
Killer and hellacious are semantically related. In some cases you can use "Killer" instead an adjective "Hellacious".
Killer
Killer adjective - Requiring considerable physical or mental effort.
Usage example: a killer exercise program guaranteed to whip you into shape
Hellacious and killer are semantically related. Sometimes you can use "Hellacious" instead an adjective "Killer".
Both words in one sentence
- Used by Clark Kent in the Smallville episode "Combat", before unleashing a hellacious beating on the superpowered killer, Titan.
Source: Now It's My Turn
Cite this Source
Killer and Hellacious. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/hellacious/killer
Hellacious & Killer. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/hellacious/killer>.
Killer or Hellacious. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/hellacious/killer.
Google Ngram Viewer shows how "hellacious" and "killer" have occurred on timeline