9
rule(noun, law, regulation, part, attitude)
8
component(noun, adjective, drop, part, material)
8
constituent(noun, adjective, drop, part, material)
8
critical(adjective, severe, important, significant, original)
8
foundation(noun, law, regulation, part, cause)
8
foundational(adjective, clear, simple, plain, pure)
8
ingrained(adjective, intrinsicality, intrinsic)
8
natural(adjective, characteristic, simple, material, essential)
8
pure(adjective, simple, pure, whole, united)
7
chief(adjective, important, significant, essential, basic)
7
cornerstone(noun, part, base, basic, basis)
7
initial(adjective, start, simple, plain, head)
7
monolithic(adjective, simple, pure, whole, united)
7
need(noun, verb, concern, demand, essential)
7
paramount(adjective, important, significant, original, essential)
7
profound(adjective, abstract, theoretical, abstruse, philosophical)
7
significant(adjective, important, original, essential, critical)
7
sine qua non(noun, expression, idiom, part, need)
6
aboriginal(adjective, harsh, violent, pure, head)
6
constitutive(adjective, important, capital, essential, critical)
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APASmart Define. (2016). fundamental thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/fundamental/thesaurus/synonyms
ChicagoSmart Define. 2016. "fundamental thesaurus" https://smartdefine.org/fundamental/thesaurus/synonyms (accessed September 24, 2026).
HarvardSmart Define 2016, fundamental thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/fundamental/thesaurus/synonyms>.
MLASmart Define. "fundamental thesaurus" 29 March 2016. Web. 24 September 2026. <https://smartdefine.org/fundamental/thesaurus/synonyms>