101 entries under hard topic. ×

11
difficult(adjective, tough, severe, evil)
9
rough(adjective, tough, nasty, difficult)
6
rugged(adjective, severe, evil, rough)
6
dangerous(adjective, tough, severe, evil)
6
knotty(adjective, severe, rough, difficult)
6
serious(adjective, bad, difficult, unpleasant)
5
complex(adjective, difficult, delicate, heavy)
5
harsh(adjective, great, severe, rough)
5
ticklish(adjective, bad, tough, difficult)
5
tricky(adjective, tough, difficult, complex)
5
troublesome(adjective, tough, severe, evil)
4
rude(adjective, rough, nasty, cruel)
4
ugly(adjective, bad, tough, severe)
3
complicated(adjective, tough, severe, rough)
3
murder(adjective, tough, severe, rough)
3
painful(adjective, tough, severe, difficult)
3
rigorous(adjective, tough, severe, rough)
3
taxing(adjective, tough, severe, rough)
2
abstruse(intense, heavy, fierce, tricky)
2
backbreaking(adjective, tough, severe, rough)
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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>