6
core(noun, adjective, support, action, cause)
6
doctrine(noun, law, rule, opinion, notion)
6
factor(noun, drop, part, material, essential)
6
indivisible(adjective, simple, pure, whole, united)
6
irreducible(adjective, simple, pure, whole, united)
6
major(adjective, important, significant, original, essential)
6
necessity(noun, condition, need, essential, essence)
6
plain(adjective, simple, pure, straightforward, basic)
6
stark(adjective, severe, pure)
6
theorem(noun, law, support, regulation, action)
6
ultimate(adjective, simple, essential, basic, surface)
5
austere(adjective, severe, pure)
5
center(noun, adjective, support, action, cause)
5
formative(adjective, pure)
5
heart(noun, support, action, part, cause)
5
homogeneous(adjective, simple, whole, united)
5
imperative(noun, adjective, law, regulation, concern)
5
introductory(adjective, start, simple, plain, head)
5
leading(adjective, important, head, significant, beginning)
5
material(noun, adjective, drop, part, important)
10 years ago|25k views|share |citing 
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>