73 entries under fundamental topic. ×

6
thoroughgoing(adjective, basic)
6
vital(adjective, great, importance, important, significant)
5
central(adjective, important, significant, original, essential)
5
chief(importance, important, significant, essential)
5
deep-seated(adjective, original, basic, primary)
5
elementary(adjective, important, significant, original, essential)
5
foundational(adjective, base, important, significant, last)
5
profound(adjective, basic)
4
bottom(adjective, important, significant, original, essential)
4
elemental(adjective, important, significant, original, essential)
4
main(importance, important, significant, original, essential)
4
utmost(adjective, great, wonderful, amazing, essential)
3
crucial(adjective, great, important, significant, original)
3
primal(adjective, basic)
2
greatest(adjective, essential, supreme)
2
key(adjective, important, significant, original, essential)
2
most(adjective, essential, supreme)
2
native(adjective, basic)
2
transcendental(adjective, essential, supreme)
2
ultimate(adjective, essential, basic, supreme)
10 years ago|28k views|share |citing 
APASmart Define. (2016). radical thesaurus. Retrieved September 28, 2026, from https://smartdefine.org/radical/thesaurus/synonyms
ChicagoSmart Define. 2016. "radical thesaurus" https://smartdefine.org/radical/thesaurus/synonyms (accessed September 28, 2026).
HarvardSmart Define 2016, radical thesaurus, Smart Define, viewed 28 September, 2026, <https://smartdefine.org/radical/thesaurus/synonyms>.
MLASmart Define. "radical thesaurus" 29 March 2016. Web. 28 September 2026. <https://smartdefine.org/radical/thesaurus/synonyms>