Doubtful and Unsubstantiated

Doubtful

Doubtful adjective - Not feeling sure about the truth, wisdom, or trustworthiness of someone or something.

Unsubstantiated and doubtful are semantically related In some cases you can use "Unsubstantiated" instead an adjective "Doubtful".

Unsubstantiated

Unsubstantiated adjective - Having no basis in reason or fact.

Doubtful and unsubstantiated are semantically related in questionable topic. You can use "Doubtful" instead an adjective "Unsubstantiated", if it concerns topics such as unreliable.

Nearby Word: unsubstantially
Cite this Source
Unsubstantiated and Doubtful. (2016). Retrieved 2026, August 01, from https://thesaurus.plus/related/doubtful/unsubstantiated
Doubtful & Unsubstantiated. N.p., 2016. Web. 01 Aug. 2026. <https://thesaurus.plus/related/doubtful/unsubstantiated>.
Unsubstantiated or Doubtful. 2016. Accessed August 01, 2026. https://thesaurus.plus/related/doubtful/unsubstantiated.
Google Ngram Viewer shows how "doubtful" and "unsubstantiated" have occurred on timeline