54 entries under problematical topic. ×

19
sticky(adjective, hard, difficult, complex, awkward)
19
toilful(adjective, hard, difficult, complex, awkward)
18
fatiguing(adjective, dull, difficult, awkward, boring)
17
grueling(adjective, hard, tough, severe, difficult)
16
troublesome(adjective, hard, tough, difficulty, difficult)
16
uphill(adjective, hard, great, tough, easy)
15
demanding(adjective, dull, hard, tough, severe)
14
tiring(adjective, dull, tough, difficult, awkward)
13
formidable(adjective, tough, severe, difficulty, rough)
13
heavy(adjective, dull, tough, severe, rough)
10
exacting(adjective, dull, hard, tough, severe)
10
wearying(adjective, dull, difficult, awkward, boring)
9
rigorous(adjective, hard, tough, severe, rough)
9
wearisome(adjective, dull, tough, severe, difficult)
7
effortful(adjective, hard, great, tough, rough)
7
terrible(adjective, difficult, tender, awkward, raw)
6
distressing(adjective, difficult, harsh, tender, cruel)
5
Herculean(adjective, tough, severe, difficult, awkward)
5
labored(adjective, hard, great, tough, rough)
5
wearing(adjective, dull, hard, tough, difficult)
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APASmart Define. (2016). arduous thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/arduous/thesaurus/synonyms
ChicagoSmart Define. 2016. "arduous thesaurus" https://smartdefine.org/arduous/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2016, arduous thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/arduous/thesaurus/synonyms>.
MLASmart Define. "arduous thesaurus" 26 February 2016. Web. 23 September 2026. <https://smartdefine.org/arduous/thesaurus/synonyms>