Doubtful and Unconceivable

Doubtful

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

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

Unconceivable

Unconceivable adjective - Too extraordinary or improbable to believe.
Usage example: it's unconceivable that a once-promising actor could end up this way

Doubtful and unconceivable are semantically related. Sometimes you can use "Doubtful" instead an adjective "Unconceivable".
Cite this Source
Unconceivable and Doubtful. (2016). Retrieved 2026, August 01, from https://thesaurus.plus/related/doubtful/unconceivable
Doubtful & Unconceivable. N.p., 2016. Web. 01 Aug. 2026. <https://thesaurus.plus/related/doubtful/unconceivable>.
Unconceivable or Doubtful. 2016. Accessed August 01, 2026. https://thesaurus.plus/related/doubtful/unconceivable.
Google Ngram Viewer shows how "doubtful" and "unconceivable" have occurred on timeline