15 entries under substantial topic. ×

15
important(adjective, serious, valuable)
10
significant(adjective, important, unimportant, serious)
10
major(adjective, dull, big, serious)
9
consequential(adjective, small, serious)
9
essential(adjective, serious)
8
weighty(adjective, light, important, serious)
7
serious(adjective, weighty, crucial)
5
meaningful(adjective, serious, little, meaningless)
4
useful(adjective, serious)
4
valuable(adjective, serious)
4
worthwhile(adjective, serious)
1
relevant(adjective, insignificant, serious, unrelated)
1
necessary(adjective, unimportant, serious)
1
pertinent(adjective, serious)
0
uncommon(adjective, serious)
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APASmart Define. (2015). trivial thesaurus. Retrieved September 28, 2026, from https://smartdefine.org/trivial/thesaurus/antonyms
ChicagoSmart Define. 2015. "trivial thesaurus" https://smartdefine.org/trivial/thesaurus/antonyms (accessed September 28, 2026).
HarvardSmart Define 2015, trivial thesaurus, Smart Define, viewed 28 September, 2026, <https://smartdefine.org/trivial/thesaurus/antonyms>.
MLASmart Define. "trivial thesaurus" 10 April 2015. Web. 28 September 2026. <https://smartdefine.org/trivial/thesaurus/antonyms>