122 entries under hard topic. ×

20
involved(adjective, difficult, complex, awkward)
20
massive(adjective, difficult, complex)
20
oppressive(adjective, difficult, complex)
20
sore(adjective, difficult, complex)
20
stubborn(adjective, strong, tough, firm)
20
troubled(adjective, difficult, unhappy, gloomy)
19
backbreaking(adjective, difficult, complex, awkward)
19
burdensome(adjective, difficult, big, heavy)
19
complicated(adjective, difficult, complex, awkward)
19
cruel(adjective, strong, tough, severe)
19
disturbing(adjective, difficult, complex)
19
esoteric(adjective, difficult, complex)
19
grinding(adjective, difficult, harsh, cruel)
19
hard-nosed(adjective, strong, tough, severe)
19
heavy(adjective, strong, great, tough)
19
intricate(adjective, difficult, complex, awkward)
19
knotty(adjective, difficult, complex, awkward)
19
ponderous(adjective, difficult, complex)
19
rough(adjective, bad, strong, tough)
19
rugged(adjective, strong, tough, difficult)
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APASmart Define. (2016). serious thesaurus. Retrieved September 25, 2026, from https://smartdefine.org/serious/thesaurus/synonyms
ChicagoSmart Define. 2016. "serious thesaurus" https://smartdefine.org/serious/thesaurus/synonyms (accessed September 25, 2026).
HarvardSmart Define 2016, serious thesaurus, Smart Define, viewed 25 September, 2026, <https://smartdefine.org/serious/thesaurus/synonyms>.
MLASmart Define. "serious thesaurus" 24 February 2016. Web. 25 September 2026. <https://smartdefine.org/serious/thesaurus/synonyms>