irregularity

IPA/ɪˌreɡjəˈlærəti/
KK[ˌɪrˌɛɡjəlˈɛrəti]IPA/ɪˌreɡjəˈlærəti/

irregularity — noun

  • irregularitysingular
  • irregularitiesplural

1. a place or area where a surface or object is not smooth, even, or symmetrical —

1.nounB2
Definition

a place or area where a surface or object is not smooth, even, or symmetrical — for example, a bump on a road, an uneven row of teeth, or an unusual mark on a wall.

Example

The dentist noticed a small irregularity on the surface of Yael's front tooth.

uncountable: 'a small irregularity' as a specific spot

Pedro felt an irregularity in the road and slowed his bicycle to inspect the spot.

Common collocations
  • surface irregularity
  • notice an irregularity
  • irregularity in [something]
  • an irregularity on [something]
Synonyms
  • unevenness

    focuses on the lack of a level surface; less technical

  • asymmetry

    specifically about lack of mirror-image balance; more formal

  • flaw

    emphasises that the irregularity is a defect or imperfection

Antonyms
  • regularity

    the quality of being even, smooth, or symmetrical

  • uniformity

    the state of being the same across the whole surface

Usage Note

Can describe both tiny flaws (a bump on a surface) and larger uneven patterns (an irregular skyline). In medical contexts it often refers to suspicious tissue growth seen on scans.

Common Mistakes

The surface had a irregularity.
The surface had an irregularity.
Because 'irregularity' starts with a vowel sound, use 'an' not 'a'.

2. an action or practice that goes against official rules, laws, or accepted standa

2.nounB2
Definition

an action or practice that goes against official rules, laws, or accepted standards of honesty and fairness — often used in contexts of financial mismanagement, administrative mistakes, or procedural errors.

Example

The bank discovered several financial irregularities in the loan department records.

countable/plural: irregularities in [area/department]

A routine audit revealed accounting irregularities that had gone unnoticed for two years.

Common collocations
  • financial irregularities
  • accounting irregularities
  • procedural irregularity
  • investigate irregularities
  • uncover irregularities
  • claims of irregularity
Synonyms
  • misconduct

    stronger term implying deliberate wrongdoing; more serious

  • breach

    focuses on the act of breaking a specific rule or agreement

  • anomaly

    more neutral; suggests something unusual that may or may not be improper

Antonyms

Usage Note

Often appears in the plural form (irregularities) since improper conduct typically involves multiple violations. The word does not necessarily mean illegal — it covers any departure from proper procedure.

Common Mistakes

The accountant was fired for irregularity.
The accountant was fired for financial irregularities.
The plural form is far more natural when referring to specific instances of misconduct.

3. the condition of an event, process, or biological function whose timing varies i

3.nounB2
Definition

the condition of an event, process, or biological function whose timing varies instead of following a predictable, steady pattern — for instance, a heartbeat that does not keep a constant rhythm or a train service that arrives at unpredictable times.

Example

Minh's doctor said the irregularity of his heartbeat needed further tests.

uncountable: 'the irregularity of [something]'

The irregularity of the bus service frustrated commuters waiting at the city-hall stop.

Common collocations
  • cardiac irregularity
  • irregularity of [something]
  • the irregularity of the heartbeat/rainfall/service
Synonyms
  • inconsistency

    broader term covering any lack of uniformity, not just timing

  • unpredictability

    emphasises the inability to know when something will happen

  • variation

    more neutral; suggests natural fluctuation rather than a problem

Antonyms

Usage Note

Uncountable when referring to the general condition ('the irregularity of the service'); countable when referring to one specific instance of uneven timing ('an irregularity in her heartbeat').

Common Mistakes

The train's irregularity annoyed me.
The irregularity of the train service annoyed me.
Specify what is irregular (the service/timing), not the train itself.

Word family

Synonym discussion

Sense: noun/2

All four words describe something that falls outside accepted norms, but they differ in seriousness and intent. An irregularity is a neutral-to-negative term for any departure from proper procedure — it could be an innocent mistake. Misconduct implies deliberate wrongdoing or negligence, carrying a stronger moral judgement. A breach is the act of breaking a specific rule, agreement, or duty, often with legal consequences. An anomaly is the most neutral term, simply meaning something unusual or unexpected; it does not necessarily imply wrongdoing at all. For example, a missing signature on a form is an irregularity (and possibly a breach of policy), but only false expense claims would be called misconduct.

irregularity ↗misconduct ↗breach ↗anomaly ↗

Common collocations

Nouns

  • surface irregularity
  • financial irregularity
  • accounting irregularity
  • cardiac irregularity
  • procedural irregularity

Adverbs

  • highly irregular

Phrases

  • claims of irregularity
  • an irregularity in [something]

Prepositions

  • irregularity in
  • irregularity on

Etymology

LatinOld FrenchEnglish

Irregularity comes from the Latin word irregularitas, meaning 'not according to rule'. It was formed from in- ('not') + regula ('rule, straight piece of wood'). The word entered English through Old French irregularité in the 14th century. Originally used to describe things that did not follow church rules, it later broadened to cover any departure from a standard shape, timing, or proper conduct.

First known use

14th century

14th century, in the meaning defined at sense 1