Highly unlikely
Unheard of and highly unlikely are semantically related. In some cases you can use "Unheard of" instead an adjective phrase "Highly unlikely".
Unheard of
Highly unlikely and unheard of are semantically related. You can use "Highly unlikely" instead an adjective phrase "Unheard of".
Cite this Source
Unheard of and Highly unlikely. (2016). Retrieved 2026, August 10, from https://thesaurus.plus/related/highly_unlikely/unheard_of
Highly unlikely & Unheard of. N.p., 2016. Web. 10 Aug. 2026. <https://thesaurus.plus/related/highly_unlikely/unheard_of>.
Unheard of or Highly unlikely. 2016. Accessed August 10, 2026. https://thesaurus.plus/related/highly_unlikely/unheard_of.
Google Ngram Viewer shows how "highly unlikely" and "unheard of" have occurred on timeline