61 entries under difficult topic. ×

10
formidable(adjective, tough, severe, awkward)
9
serious(adjective, hard, tough, importance)
8
severe(adjective, hard, tough, awkward)
6
demanding(adjective, hard, tough, severe)
5
arduous(adjective, hard, great, tough, severe)
4
exhausting(adjective, hard, tough, awkward)
4
laborious(adjective, great, tough, severe)
4
rigorous(adjective, awkward, thorough, demanding)
3
hard(adjective, great, tough, awkward)
3
rough(adjective, great, tough, terrible)
3
trying(adjective, hard, tough, severe)
2
awkward(adjective, contrary, demanding, tricky)
2
burdensome(adjective, tough, severe, awkward)
2
effortful(adjective, great, tough, severe)
2
exacting(adjective, hard, tough, severe)
2
onerous(adjective, hard, great, tough, severe)
2
problematical(adjective, awkward, demanding, tricky)
2
rugged(adjective, awkward, demanding, grueling)
2
strenuous(adjective, great, tough, severe)
2
toilsome(adjective, great, tough, severe)
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APASmart Define. (2016). challenging thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/challenging/thesaurus/synonyms
ChicagoSmart Define. 2016. "challenging thesaurus" https://smartdefine.org/challenging/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2016, challenging thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/challenging/thesaurus/synonyms>.
MLASmart Define. "challenging thesaurus" 2 March 2016. Web. 22 September 2026. <https://smartdefine.org/challenging/thesaurus/synonyms>