Flat
Flat adjective - Having been established and usually not subject to change.
Usage example: charged a flat rate for overseas calls
Inexpugnable and flat are semantically related. In some cases you can use "Inexpugnable" instead an adjective "Flat".
Inexpugnable
Inexpugnable adjective - Having been established and usually not subject to change.
Usage example: an inexpugnable belief in the essential goodness of people
Flat and inexpugnable are semantically related. Sometimes you can use "Flat" instead an adjective "Inexpugnable".
Cite this Source
Inexpugnable and Flat. (2016). Retrieved 2026, July 22, from https://thesaurus.plus/related/flat/inexpugnable
Flat & Inexpugnable. N.p., 2016. Web. 22 Jul. 2026. <https://thesaurus.plus/related/flat/inexpugnable>.
Inexpugnable or Flat. 2016. Accessed July 22, 2026. https://thesaurus.plus/related/flat/inexpugnable.
Google Ngram Viewer shows how "flat" and "inexpugnable" have occurred on timeline