3
exceptional
3
forceful(adjective, prevailing, influential, commanding)
3
gargantuan
3
grave(adjective, tough, severe, difficult, unpleasant)
3
hair-raising(adjective, awful, terrible, shocking, dreadful)
3
hearty
3
hideous(adjective, bad, awful, terrible, disgusting)
3
high(adjective, lofty, tall, elevated, towering)
3
horrid(appearance, awful, terrible, fear, disgusting)
3
incredible
3
mean(adjective, bad, severe, rough, nasty)
3
mind-blowing(awful, wonderful, amazing, grand, splendid)
3
mind-boggling
3
murder(adjective, hard, tough, severe, rough)
3
oppressive(adjective, difficult, heavy)
3
overpowering(adjective, difficult, powerful, overwhelming)
3
painful(adjective, hard, tough, severe, difficult)
3
portentous(adjective, fear)
3
puissant(adjective, tough, difficult, overwhelming, prevailing)
3
rigorous(adjective, hard, tough, severe, rough)
11 years ago|23k views|share |citing 
APASmart Define. (2015). formidable thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/formidable/thesaurus/synonyms
ChicagoSmart Define. 2015. "formidable thesaurus" https://smartdefine.org/formidable/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2015, formidable thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/formidable/thesaurus/synonyms>.
MLASmart Define. "formidable thesaurus" 17 July 2015. Web. 20 September 2026. <https://smartdefine.org/formidable/thesaurus/synonyms>