Irregulaire

Irregulaire is a French adjective meaning "not regular," indicating something that deviates from a standard pattern or norm. The word originates from the prefix ir‑, combined with the root réguler, derived from Latin regere (to rule). In modern French, it is frequently used in contexts where regularity or conformity is expected.

In French grammar, irregulaire describes verbs whose conjugation does not follow the conventional patterns of the first, second, or third conjugation groups. French has a large class of irregular verbs such as être, avoir, aller, faire, et être, whose forms must be memorised. The term also applies to irregular nouns, adjectives, or pronouns that undergo atypical changes in gender, number, or case.

Beyond linguistics, irregulaire appears in other disciplines. In mathematics, an irregular figure refers to a shape lacking symmetry or consistent angles, such as an irregular polygon. In economics and finance, irregular payments or irregular incomes denote cash flows that vary unpredictably over time. Legal and administrative documents may use the term to label irregular procedures or irregular facilities that do not meet established regulations.

The adjective is also applied descriptively in everyday speech, for example when referring to an irregular heartbeat (un rythme cardiaque irrégulier), irregular weather patterns (météo irrégulière), or irregular behaviour (comportement irrégulier). Because irregulaire captures the idea of deviation from the expected, it is widely used in French to contrast regularity with exceptions or anomalies across a diverse range of subjects.