Definition of unsubstantiated
: not proven to be true : not substantiated an unsubstantiated rumor/report a plausible but unsubstantiated theory
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First Known Use of unsubstantiated
circa 1775
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Thesaurus: All synonyms and antonyms for unsubstantiated Spanish Central: Translation of unsubstantiated Nglish: Translation of unsubstantiated for Spanish speakers
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