75 entries under difficult topic. ×

4
exhausting(adjective, hard, rough, heavy)
4
grueling(adjective, hard, tough, awkward)
4
operose(adjective, tough, severe, rough)
4
painful(hard, tough, severe, problematic)
4
rigorous(adjective, hard, tough, severe, rough)
4
tricky(adjective, tough, complex, awkward)
4
wearying(adjective, tough, rough, heavy)
3
complex
3
exacting(adjective, tough, severe, rough)
3
grinding(adjective, tough, rough, heavy)
3
heavy(adjective, tough, severe, rough)
3
oppressive
3
taxing(adjective, hard, severe, rough)
3
thorny
3
ticklish
3
tight
3
tiring(adjective, hard, tough, rough)
3
trying(adjective, tough, severe, rough)
2
Herculean(adjective, tough, severe, awkward)
2
backbreaking(adjective, hard, tough, severe, rough)
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APASmart Define. (2015). uphill thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/uphill/thesaurus/synonyms
ChicagoSmart Define. 2015. "uphill thesaurus" https://smartdefine.org/uphill/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, uphill thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/uphill/thesaurus/synonyms>.
MLASmart Define. "uphill thesaurus" 10 April 2015. Web. 22 September 2026. <https://smartdefine.org/uphill/thesaurus/synonyms>