73 entries under fundamental topic. ×

16
essential(adjective, importance, important, significant, original)
14
root(noun, adjective, cause, original, basic)
14
prime(importance, important, job, significant, original)
13
basic(adjective, base, important, significant, last)
12
original(noun, adjective, cause, important, new)
11
primary(adjective, cause, base, importance, important)
10
organic(adjective, important, significant, original, essential)
9
basal(adjective, base, important, significant, last)
9
underlying(adjective, base, important, significant, last)
8
inherent(adjective, essential, basic, key)
7
capital(importance, job, essential, key)
7
cardinal(adjective, importance, important, significant, original)
7
constitutional(adjective, important, significant, original, essential)
7
ingrained(adjective, intrinsicality)
7
natural(adjective, new, hot, raw, essential)
7
primitive(adjective, cause, important, significant, original)
6
innate(adjective, basic, intrinsicality)
6
intrinsic(adjective, important, significant, original, essential)
6
principal(adjective, great, importance, important, significant)
6
superlative(adjective, job, essential, very best kind)
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APASmart Define. (2016). radical thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/radical/thesaurus/synonyms
ChicagoSmart Define. 2016. "radical thesaurus" https://smartdefine.org/radical/thesaurus/synonyms (accessed September 26, 2026).
HarvardSmart Define 2016, radical thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/radical/thesaurus/synonyms>.
MLASmart Define. "radical thesaurus" 29 March 2016. Web. 26 September 2026. <https://smartdefine.org/radical/thesaurus/synonyms>