84 entries under fundamental topic. ×

11
radical(adjective, cause, base, importance, important)
11
vital(adjective, body, importance, material, big)
10
introductory(adjective, simple, plain, head, beginning)
8
ultimate(adjective, essential, supreme, intervening)
7
simple(adjective, top, pure, straightforward, basic)
6
constitutional(adjective, body, material, important, significant)
6
crucial(adjective, big, important, significant, original)
6
foundational(adjective, simple, plain, base, pure)
6
opening(adjective, head, beginning, original, basic)
4
early(adjective, simple, head, beginning, original)
4
embryonic(cause, simple, original, basic)
4
indispensable(adjective, important, significant, original, serious)
4
material(adjective, body, big, important, significant)
4
necessary(adjective, body, material, big, important)
3
abecedarian(adjective, simple, straightforward, basic)
3
bottom(adjective, important, significant, original, essential)
3
critical(adjective, big, important, significant, substantial)
3
inherent(adjective, body, material, natural, animate)
3
intrinsic(adjective, important, significant, original, essential)
2
connate(adjective, cause, basic, absolute)
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APASmart Define. (2016). primary thesaurus. Retrieved September 25, 2026, from https://smartdefine.org/primary/thesaurus/synonyms
ChicagoSmart Define. 2016. "primary thesaurus" https://smartdefine.org/primary/thesaurus/synonyms (accessed September 25, 2026).
HarvardSmart Define 2016, primary thesaurus, Smart Define, viewed 25 September, 2026, <https://smartdefine.org/primary/thesaurus/synonyms>.
MLASmart Define. "primary thesaurus" 29 March 2016. Web. 25 September 2026. <https://smartdefine.org/primary/thesaurus/synonyms>