Grim
Grim adjective - Harsh and threatening in manner or appearance.
Hellacious and grim are semantically related. In some cases you can use "Hellacious" instead an adjective "Grim".
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
Grim and hellacious are semantically related. Sometimes you can use "Grim" instead an adjective "Hellacious".
Mutual synonyms
Cite this Source
Hellacious and Grim. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/grim/hellacious
Grim & Hellacious. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/grim/hellacious>.
Hellacious or Grim. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/grim/hellacious.
Google Ngram Viewer shows how "grim" and "hellacious" have occurred on timeline