67 entries under complex topic. ×

19
leaden(adjective, hard, difficult)
19
ponderous(adjective, hard, difficult)
19
problematic(adjective, hard, tough, difficult)
19
profound(adjective, hard, difficult)
19
sophisticated(adjective, hard, difficult, intricate)
19
sticky(adjective, hard, difficult, awkward)
19
toilful(adjective, hard, difficult, awkward)
16
troublesome(adjective, hard, tough, difficulty, difficult)
2
abstruse(adjective, hard, fancy, difficult)
2
dense(adjective, difficult, intricate, thorny)
1
Daedalean(adjective, hard, fancy, difficult)
1
can of worms(expression, adjective, idiom, hard, fancy)
1
convoluted(adjective, hard, fancy, difficult)
1
entangled(adjective, hard, fancy, difficult)
1
fancy(adjective, hard, difficult, intricate)
1
gasser(adjective, hard, fancy, difficult)
1
hi-tech(adjective, hard, fancy, difficult)
1
interlaced(adjective, hard, fancy, difficult)
1
mega factor(expression, adjective, hard, fancy, difficult)
1
mixed(adjective, hard, fancy, difficult)
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APASmart Define. (2016). arduous thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/arduous/thesaurus/synonyms
ChicagoSmart Define. 2016. "arduous thesaurus" https://smartdefine.org/arduous/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2016, arduous thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/arduous/thesaurus/synonyms>.
MLASmart Define. "arduous thesaurus" 26 February 2016. Web. 20 September 2026. <https://smartdefine.org/arduous/thesaurus/synonyms>