Improper
Improper adjective - Not conforming to legality, moral law, or social convention.
Usage example: improper banking practices
Irregular is a synonym for improper in inappropriate topic. In some cases you can use "Irregular" instead an adjective "Improper", when it comes to topics like incorrect, not suitable.
Nearby Word: improperly
Irregular
Irregular adjective - Contrary to rule or accepted order or general practice.
Usage example: irregular hiring practices
Improper is a synonym for irregular in inappropriate topic. You can use "Improper" instead an adjective "Irregular", if it concerns topics such as abnormal, against the rules.
Nearby Words: irregularity, irregularly
Mutual synonyms
Cite this Source
Irregular and Improper. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/improper/irregular
Improper & Irregular. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/improper/irregular>.
Irregular or Improper. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/improper/irregular.
Google Ngram Viewer shows how "improper" and "irregular" have occurred on timeline