66 entries under complex topic. ×

69
deep(noun, adjective, good, feeling, strong)
33
serious(adjective, hard, difficult, deep)
32
esoteric(adjective, hard, easy, obscure, difficult)
28
difficult(adjective, hard, thoughtful, intellectual)
27
hard(adjective, difficult, intense, emotional)
25
weighty(adjective, hard, difficult, thoughtful)
25
severe(adjective, hard, difficult, intense)
24
knotty(adjective, hard, difficult)
23
intricate(adjective, hard, difficult)
23
involved(adjective, hard, difficult)
23
tricky(adjective, hard, difficult, cunning)
22
laborious(adjective, hard, difficult)
21
thorny(adjective, hard, difficult)
20
arduous(adjective, hard, difficult)
19
grave(adjective, hard, difficult, greatness)
19
grievous(adjective, hard, difficult)
19
sophisticated(adjective, hard, difficult, intelligent)
19
backbreaking(adjective, hard, difficult)
19
complicated(adjective, hard, difficult)
19
heartrending(adjective, hard, difficult, intense)
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APASmart Define. (2016). profound thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/profound/thesaurus/synonyms
ChicagoSmart Define. 2016. "profound thesaurus" https://smartdefine.org/profound/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2016, profound thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/profound/thesaurus/synonyms>.
MLASmart Define. "profound thesaurus" 26 February 2016. Web. 20 September 2026. <https://smartdefine.org/profound/thesaurus/synonyms>