Translation guide
The English word 'irregular' covers a wide range of meanings including not following rules, uneven patterns, non-standard forms, and occasional occurrences. This guide organizes the most useful Japanese expressions by these core meanings.
Describing something that deviates from standard rules, procedures, or expectations.
The most direct and common translation for 'irregular' in the sense of not following a regular pattern or rule. Used for schedules, shapes, verbs, etc.
He leads an irregular lifestyle.
This verb has an irregular conjugation.
Emphasizes deviation from normal rules or methods, often used for procedures or systems.
It was approved through an irregular procedure.
A loanword from English, commonly used in business or casual contexts to mean something out of the ordinary or an exception.
We need to handle this irregularly today.
Describing shapes, surfaces, or patterns that are not uniform or smooth.
Used for things that are uneven in size, shape, or alignment, like teeth, vegetables, or rows.
Irregularly shaped vegetables look fresher.
Describes a bumpy, uneven surface. Often used for roads or skin.
Can also be used for irregular patterns or shapes, but less specific than 不揃い.
Describing events that happen from time to time, not regularly scheduled.
Means 'irregular' in the sense of not having a fixed time or schedule. Common for meetings, publications, or work.
This meeting is held irregularly.
Simply means 'sometimes' or 'occasionally'. Less formal and very common in speech.
Describing something that is not typical or deviates from the norm, often in a technical or medical context.
Means 'abnormal' or 'irregular' in a medical, technical, or statistical sense. Can imply something is wrong.
An irregular waveform is seen on the ECG.
Irregular weather patterns continue.
Used for something that deviates from the norm, especially in rules or systems. Similar to 変則的 but as a noun.
Referring to words that do not follow standard conjugation or declension patterns.
不規則 (fukisoku) means lacking a regular pattern or rule, while 不定期 (futeiki) specifically means not having a fixed time or schedule. Use 不規則 for shapes, verb forms, or lifestyle; use 不定期 for events or publications.
イレギュラー is a loanword and sounds casual. In formal writing or technical contexts, prefer 不規則 or 変則的.
この道はでこぼこしていて歩きにくい。
This road is irregular and hard to walk on.
不規則な形の石
an irregularly shaped stone
He works part-time on an irregular basis.
彼は時々遅刻する。
He is occasionally late.
変則的な勤務体系
an irregular work system