unregelmäßig

Unregelmäßig is an adjective and adverb in German that denotes something not regular, not occurring at fixed intervals, or lacking a fixed pattern. It is formed from un- plus regelmäßig, the latter meaning regular or following a rule. The term is used across different domains to indicate deviation from standard order or timing.

In linguistics and grammar, unregelmäßig describes verbs whose conjugation does not follow the regular patterns of a language’s verbs. In German, unregelmäßige Verben (irregular verbs) often show stem-vowel changes or irregular endings. Examples include gehen (ich gehe, du gehst, er geht) and sehen (ich sehe, du siehst, er sieht). This group is commonly divided into strong, weak, and mixed verbs, reflecting different ways forms change.

In timekeeping and event scheduling, unregelmäßig refers to processes or occurrences that do not follow a fixed timetable or interval. Phrases such as unregelmäßige Abstände or unregelmäßige Arbeitszeiten describe irregular timing or frequency.

The term also appears in medical and scientific contexts to describe rhythms or patterns that are not regular, for example unregelmäßiger Herzschlag or unregelmäßige Menstruation, as well as in mathematics or design to describe shapes or sequences lacking periodicity or symmetry.

Antonyms include regelmäßig, planmäßig, and systematisch. Related terms are Unregelmäßigkeit (irregularity) and Unregelmäßigkeiten. The nuance of unregelmäßig centers on deviation from a standard rule, rhythm, or pattern, and its interpretation depends on the domain of use.