Firm
Firm adjective - Not showing weakness or uncertainty.
Impassable and firm are semantically related. In some cases you can use "Impassable" instead an adjective "Firm".
Impassable
Impassable adjective - Impossible to get through or into.
Usage example: the road was impassable until snowplows cleared it
Firm and impassable are semantically related. Sometimes you can use "Firm" instead an adjective "Impassable".
Nearby Words: impasse, impassible
Mutual synonyms
Cite this Source
Impassable and Firm. (2016). Retrieved 2026, August 16, from https://thesaurus.plus/related/firm/impassable
Firm & Impassable. N.p., 2016. Web. 16 Aug. 2026. <https://thesaurus.plus/related/firm/impassable>.
Impassable or Firm. 2016. Accessed August 16, 2026. https://thesaurus.plus/related/firm/impassable.
Google Ngram Viewer shows how "firm" and "impassable" have occurred on timeline