Formal and Irregular

Formal

Formal adjective - Following or agreeing with established form, custom, or rules.
Usage example: a formal contract that was legally binding

Irregular is an antonym for formal.

Irregular

Irregular adjective - Not rigidly following established form, custom, or rules.
Usage example: the request is irregular, but I'll allow it

Formal is an antonym for irregular.

Nearby Words: irregularity, irregularly

Both words in one sentence

Cite this Source
Irregular and Formal. (2016). Retrieved 2026, July 22, from https://thesaurus.plus/related/formal/irregular
Formal & Irregular. N.p., 2016. Web. 22 Jul. 2026. <https://thesaurus.plus/related/formal/irregular>.
Irregular or Formal. 2016. Accessed July 22, 2026. https://thesaurus.plus/related/formal/irregular.
Google Ngram Viewer shows how "formal" and "irregular" have occurred on timeline