Synonyms|1.4kAntonyms|650|Broader|15Narrower|0Related|2.9k
1
foul
1
fragile
1
frail
1
frivolous
1
gossamery
1
half-pint
1
hypothetical
1
illusory
1
imaginary(adjective, fictitious, invented)
1
impalpable(adjective, unsubstantial, intangible)
1
imperceptible
1
impoverished
1
incidental
1
inessential
1
invented
1
jejune
1
lacking
1
light
1
lilliputian
1
little-bitty
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APASmart Define. (2016). substantial thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/substantial/thesaurus/antonyms
ChicagoSmart Define. 2016. "substantial thesaurus" https://smartdefine.org/substantial/thesaurus/antonyms (accessed September 23, 2026).
HarvardSmart Define 2016, substantial thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/substantial/thesaurus/antonyms>.
MLASmart Define. "substantial thesaurus" 24 March 2016. Web. 23 September 2026. <https://smartdefine.org/substantial/thesaurus/antonyms>