62 entries under main topic. ×

10
necessary(adjective, base, basic, prime, key)
7
primary(adjective, base, important, essential, basic)
7
key(adjective, base, important, essential, basic)
6
principal(adjective, base, important, essential, basic)
6
central(adjective, base, important, essential, basic)
6
crucial(adjective, important, essential, prime)
6
major(adjective, important, essential, prime)
6
needed(verb, adjective, prime, major)
6
vital(adjective, base, important, essential, basic)
5
cardinal(adjective, important, essential, prime)
5
chief(adjective, base, basic, prime, key)
5
prime(adjective, important, essential, chief)
5
capital(adjective, base, important, essential, basic)
5
leading(adjective, important, essential, prime, vital)
5
premier(adjective, important, essential, prime)
5
underlying(adjective, base, essential, basic, prime)
5
ruling(adjective, important, essential, prime, vital)
4
essential(adjective, base, basic, prime, key)
4
significant(adjective, important, essential, prime)
3
foremost(adjective, adverb, important, master, essential)
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APASmart Define. (2015). ancillary thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/ancillary/thesaurus/antonyms
ChicagoSmart Define. 2015. "ancillary thesaurus" https://smartdefine.org/ancillary/thesaurus/antonyms (accessed September 23, 2026).
HarvardSmart Define 2015, ancillary thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/ancillary/thesaurus/antonyms>.
MLASmart Define. "ancillary thesaurus" 10 April 2015. Web. 23 September 2026. <https://smartdefine.org/ancillary/thesaurus/antonyms>