66 entries under essential topic. ×

4
central(adjective, top, important, significant, original)
4
constitutional(adjective, important, significant, original)
4
indispensable(adjective, important, significant, original)
4
key(adjective, important, significant, original)
4
main(adjective, top, original, basic)
4
necessary(adjective, important, significant, original)
3
capital(adjective, fundamental, key, main)
3
integral(adjective, important, significant, original)
2
chief(adjective, top, prime, vital)
2
congenital(adjective, basic, absolute, fundamental)
2
constitutive(important, original, basic, vital)
2
first(adjective, rough, important, significant, original)
2
important(adjective, significant, original, basic)
2
inborn(adjective, basic, absolute, fundamental)
2
innate(adjective, basic, absolute, fundamental)
2
material(adjective, basic, absolute, fundamental)
2
staple
2
substratal(adjective, simple, plain, important, significant)
1
axiological(adjective, important, significant, original)
1
connate(adjective, basic, absolute, fundamental)
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APASmart Define. (2015). underlying thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/underlying/thesaurus/synonyms
ChicagoSmart Define. 2015. "underlying thesaurus" https://smartdefine.org/underlying/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, underlying thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/underlying/thesaurus/synonyms>.
MLASmart Define. "underlying thesaurus" 10 April 2015. Web. 22 September 2026. <https://smartdefine.org/underlying/thesaurus/synonyms>