Often doubtful
Unproven and often doubtful are semantically related. In some cases you can use "Unproven" instead an adjective phrase "Often doubtful".
Unproven
Unproven adjective - Not proved.
Often doubtful and unproven are semantically related. You can use "Often doubtful" instead an adjective "Unproven".
Mutual synonyms
Cite this Source
Unproven and Often doubtful. (2016). Retrieved 2026, August 16, from https://thesaurus.plus/related/often_doubtful/unproven
Often doubtful & Unproven. N.p., 2016. Web. 16 Aug. 2026. <https://thesaurus.plus/related/often_doubtful/unproven>.
Unproven or Often doubtful. 2016. Accessed August 16, 2026. https://thesaurus.plus/related/often_doubtful/unproven.
Google Ngram Viewer shows how "often doubtful" and "unproven" have occurred on timeline