Improper
Improper adjective - Not appropriate for a particular occasion or situation.
Perfidious and improper are semantically related. In some cases you can use "Perfidious" instead an adjective "Improper".
Nearby Word: improperly
Perfidious
Perfidious adjective - Not true in one's allegiance to someone or something.
Improper and perfidious are semantically related. Sometimes you can use "Improper" instead an adjective "Perfidious".
Nearby Words: perfidy, perfidiously
Cite this Source
Perfidious and Improper. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/improper/perfidious
Improper & Perfidious. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/improper/perfidious>.
Perfidious or Improper. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/improper/perfidious.
Google Ngram Viewer shows how "improper" and "perfidious" have occurred on timeline