Unsubstantiated and Valid

Opposite meaning words

Unsubstantiated adjective - Having no basis in reason or fact.

Usage example: an unsubstantiated claim that was thrown out of court

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Valid is an antonym for unsubstantiated.

Nearby Word: unsubstantially

Valid adjective - Based on sound reasoning or information.

Usage example: only further investigation will show whether your theory is valid

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Unsubstantiated is an antonym for valid.

Nearby Words: validity, validation

Cite this Source

Valid and Unsubstantiated. (2016). Retrieved 2026, August 14, from https://thesaurus.plus/related/unsubstantiated/valid

Unsubstantiated & Valid. N.p., 2016. Web. 14 Aug. 2026. <https://thesaurus.plus/related/unsubstantiated/valid>.

Valid or Unsubstantiated. 2016. Accessed August 14, 2026. https://thesaurus.plus/related/unsubstantiated/valid.

Google Ngram Viewer shows how "unsubstantiated" and "valid" have occurred on timeline