Illegal
Illegal adjective - Prohibited by law or by official or accepted rules.
Usage example: an illegal chess move
Irregular is a synonym for illegal in against the law topic. In some cases you can use "Irregular" instead the word "Illegal" as an adjective or a noun.
Nearby Words: illegality, illegally
Irregular
Irregular adjective - Contrary to rule or accepted order or general practice.
Usage example: irregular hiring practices
Illegal is a synonym for irregular. Sometimes you can use "Illegal" instead the word "Irregular" as an adjective or a noun.
Nearby Words: irregularity, irregularly
Mutual synonyms
Cite this Source
Irregular and Illegal. (2016). Retrieved 2026, August 15, from https://thesaurus.plus/related/illegal/irregular
Illegal & Irregular. N.p., 2016. Web. 15 Aug. 2026. <https://thesaurus.plus/related/illegal/irregular>.
Irregular or Illegal. 2016. Accessed August 15, 2026. https://thesaurus.plus/related/illegal/irregular.
Google Ngram Viewer shows how "illegal" and "irregular" have occurred on timeline