81 entries under key topic. ×

17
central(adjective, important, significant, original, basic)
16
cardinal(adjective, importance, important, significant, original)
16
inborn(adjective, characteristic, reasonable, common, ordinary)
16
substantial(adjective, physical, importance, material, big)
15
deep-seated(adjective, characteristic, natural, original, basic)
14
core(adjective, support, action, base, importance)
14
critical(adjective, severe, big, important, significant)
14
inbred(adjective, characteristic, natural, individual, basic)
14
underlying(adjective, simple, plain, important, significant)
13
leading(adjective, feature, state, characteristic, importance)
12
radical(adjective, importance, important, significant, original)
11
grave(adjective, severe, importance, big, important)
11
meaningful(adjective, importance, big, important, significant)
11
serious(adjective, severe, importance, big, important)
11
weighty(adjective, importance, big, important, significant)
10
first(adjective, important, significant, original, prominent)
10
relevant(adjective, importance, big, significant, substantial)
9
basal(adjective, body, simple, plain, material)
9
capital(adjective, importance, important, prominent, prime)
9
influential(adjective, importance, big, important, significant)
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APASmart Define. (2016). essential thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/essential/thesaurus/synonyms
ChicagoSmart Define. 2016. "essential thesaurus" https://smartdefine.org/essential/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2016, essential thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/essential/thesaurus/synonyms>.
MLASmart Define. "essential thesaurus" 31 March 2016. Web. 23 September 2026. <https://smartdefine.org/essential/thesaurus/synonyms>