Implacable
Implacable adjective - Sticking to an opinion, purpose, or course of action in spite of reason, arguments, or persuasion.
Usage example: an implacable judge who knew in his bones that the cover-up extended to the highest levels of government
Rigid is a synonym for implacable in headstrong topic. In some cases you can use "Rigid" instead an adjective "Implacable", when it comes to topics like resist.
Nearby Words: implacability, implacably
Rigid
Rigid adjective - Not allowing for any exceptions or loosening of standards.
Usage example: rigid enforcement of drug laws
Implacable is a synonym for rigid in headstrong topic. You can use "Implacable" instead an adjective "Rigid", if it concerns topics such as resist.
Mutual synonyms
Cite this Source
Rigid and Implacable. (2016). Retrieved 2026, August 14, from https://thesaurus.plus/related/implacable/rigid
Implacable & Rigid. N.p., 2016. Web. 14 Aug. 2026. <https://thesaurus.plus/related/implacable/rigid>.
Rigid or Implacable. 2016. Accessed August 14, 2026. https://thesaurus.plus/related/implacable/rigid.
Google Ngram Viewer shows how "implacable" and "rigid" have occurred on timeline