Illegal
Illegal adjective - Contrary to or forbidden by law.
Improper and illegal are semantically related. In some cases you can use "Improper" instead an adjective "Illegal".
Nearby Words: illegality, illegally
Improper
Improper adjective - Not appropriate for a particular occasion or situation.
Illegal and improper are semantically related. Sometimes you can use "Illegal" instead an adjective "Improper".
Nearby Word: improperly
Mutual synonyms
Cite this Source
Improper and Illegal. (2016). Retrieved 2026, July 22, from https://thesaurus.plus/related/illegal/improper
Illegal & Improper. N.p., 2016. Web. 22 Jul. 2026. <https://thesaurus.plus/related/illegal/improper>.
Improper or Illegal. 2016. Accessed July 22, 2026. https://thesaurus.plus/related/illegal/improper.
Google Ngram Viewer shows how "illegal" and "improper" have occurred on timeline