77 entries under severe topic. ×

3
wearisome(adjective, tough, difficult, awkward)
2
backbreaking(adjective, hard, tough, rough)
2
bothersome(adjective, tough, difficult, awkward)
2
difficile(adjective, tough, rough, difficult)
2
distressing(adjective, bad, tough, rough)
2
exhausting(adjective, hard, tough, rough)
2
fateful(adjective, tough, important, significant)
2
grievous(adjective, tough, difficult, unpleasant)
2
grinding(adjective, tough, rough, difficult)
2
intricate(adjective, hard, tough, difficult)
2
tiring(adjective, hard, tough, rough)
2
violent(adjective, hard, rough, difficult)
1
deep(adjective, hard, tough, delicate)
1
far-reaching(adjective, tough, important, significant)
1
fatiguing(adjective, hard, tough, rough)
1
grueling(adjective, hard, tough, difficult)
1
irksome(adjective, tough, difficulty, rough)
1
major(adjective, tough, unpleasant, important)
1
meaning business(expression, adjective, tough, important)
1
meaningful(adjective, tough, important, significant)
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APASmart Define. (2015). formidable thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/formidable/thesaurus/synonyms
ChicagoSmart Define. 2015. "formidable thesaurus" https://smartdefine.org/formidable/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, formidable thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/formidable/thesaurus/synonyms>.
MLASmart Define. "formidable thesaurus" 17 July 2015. Web. 22 September 2026. <https://smartdefine.org/formidable/thesaurus/synonyms>