irregular

adjective ir·reg·u·lar \ i-ˈre-gyə-lər , ˌi(r)- \

Definition of irregular

1 a :not being or acting in accord with laws, rules, or established custom

irregular conduct

b :not conforming to the usual pattern of inflection

irregular verbs

; specifically :strong 16

c :not following a usual or prescribed procedure; especially, British :celebrated without either proclamation of the banns or publication of intention to marry

irregular marriage

2 :not belonging to or a part of a regular organized group; specifically :not belonging to a regular army but raised for a special purpose

irregular troops

3 a :lacking perfect symmetry or evenness

an irregular coastline

b :having one or more floral parts of the same whorl different in size, shape, or arrangement; specifically :zygomorphic

4 :lacking continuity or regularity especially of occurrence or activity

irregular employment

—

irregularly

adverb

See irregular defined for English-language learners

See irregular defined for kids

Examples of irregular in a Sentence

His behavior as a teacher was highly irregular.
Her application was handled in an irregular manner.
a very jagged, irregular surface
The stone has an irregular shape.
He has a very irregular schedule.
The festival has been held at irregular intervals.

Recent Examples of irregular from the Web

This type of planet, at that distance from a star, would dim the star's light in an irregular way during a transit.

— david grossman, Popular Mechanics, "New Theory for "Alien Megastructure": A Planet Like Saturn, But Close To The Sun," 25 Aug. 2017
In situations of irregular light and darkness, everything goes out of whack within a couple of days.

— patrick blanchfield, Esquire, "Shot in the Dark," 1 Aug. 2017
The data is then collated into an annual report and published at irregular intervals.

— christopher harress, AL.com, "Alabama unemployment low, part-time jobs up, but why?," 20 July 2017
Working quickly and aggressively, rub butter into dry ingredients with your fingertips and palms to smash butter into flour and incorporate completely, creating some pieces that are flat and thin and some that are pea-sized and irregular.

— rick martinez, Bon Appetit, "BA's Best Blueberry Pie," 10 July 2017
The last rider to be disqualified from the Tour for irregular riding was Cavendish’s teammate and leadout specialist (winds up the speed for the sprinter) Mark Renshaw, who headbutted one rider, then rode another one toward the barriers.

— kevin williams, chicagotribune.com, "Did officials make the right call in DQing Peter Sagan? A racing cyclist weighs in," 5 July 2017
The smallest particulates have been linked to premature death in people with heart or lung disease, heart attacks, irregular heartbeats, aggravated asthma and other lung problems.

— james bruggers, The Courier-Journal, "Fireworks may have been a blast, but they sent Louisville pollution levels soaring," 5 July 2017
Little is known about these shallow, irregular depressions that dot the surface.

— david grossman, Popular Mechanics, "How a Probe Will Chase Down Mercury Over 7 Years," 5 July 2017
Heavy and/or irregular menstrual bleeding is common during early adolescence.

— joanna davis, m.d., miamiherald, "Teens’ heavy menstrual cycles could be indication of blood disorders," 26 June 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'irregular.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of irregular

Middle English irreguler, from Anglo-French, from Late Latin irregularis not in accordance with rule, from Latin in- + regularis regular

NEW! Time Traveler

First Known Use: 14th century

See Words from the same year

irregular Synonyms

Synonyms

aberrant, aberrational, abnormal, anomalous, atypical, deviate, devious, deviant, unnatural, untypical

Antonyms

natural, normal, regular, standard, typical

Near Antonyms

common, commonplace, everyday, familiar, ordinary, routine, run-of-the-mill, run-of-the-mine (or run-of-mine), unexceptional, unremarkable, workaday; customary, usual, wonted; archetypal (also archetypical), average, characteristic, representative

Synonym Discussion of irregular

irregular, anomalous, unnatural mean not conforming to rule, law, or custom. irregular implies not conforming to a law or regulation imposed for the sake of uniformity in method, practice, or conduct.

- concerned about his irregular behavior

anomalous implies not conforming to what might be expected because of the class or type to which it belongs or the laws that govern its existence.

- her drive made her an anomalous figure in a sleepy organization

unnatural suggests what is contrary to nature or to principles or standards felt to be essential to the well-being of civilized society.

- prisoners treated with unnatural cruelty

irregular

noun

Definition of irregular

:one that is irregular: such as

a :a soldier who is not a member of a regular military force

b irregulars plural :merchandise that has minor defects or that falls next below the manufacturer's standard for firsts

See irregular defined for English-language learners

Recent Examples of irregular from the Web

The coalition argues that casualties are inevitable in urban warfare with irregulars mixing with civilians and determined to stage a last stand.

— susanna george, The Seattle Times, "Civilian casualty toll could complicate Iraqi reconciliation," 1 May 2017
Elite units, regular troops, irregulars in jeans carrying Kalashnikovs, members of foreign militias and armored vehicles could be seen near the front line on Sunday and Monday.

— anne barnard, New York Times, "Resurgent Syrian Rebels Surprise Damascus With New Assaults," 21 Mar. 2017
His small band of irregulars skirmished with government troops, and each encounter increased their support in Cuba and around the world, even though other insurgent forces in the cities were also fighting to overthrow the Batista government.

— anthony depalma, New York Times, "Fidel Castro, Cuban Revolutionary Who Defied U.S., Dies at 90," 26 Nov. 2016

First Known Use of irregular

15th century

IRREGULAR Defined for English Language Learners

irregular

adjective

Definition of irregular for English Language Learners

: not normal or usual : not following the usual rules about what should be done
: not even or smooth : not regular in form or shape
: happening or done at different times that change often

irregular

noun

Definition of irregular for English Language Learners

: a soldier who does not belong to a country's official army

IRREGULAR Defined for Kids

irregular

adjective ir·reg·u·lar \ i-ˈreg-yə-lər \

Definition of irregular for Students

1 :not following custom or rule

Her methods are most irregular.

2 :not following the usual manner of inflection

The verb “sell” is irregular because its past tense is “sold,” not “selled.”

3 :not straight, smooth, or even

an irregular coastline

4 :not continuous or coming at set times

He works irregular hours.

—

irregularly

adverb

Medical Dictionary

irregular

adjective ir·reg·u·lar \ (ˈ)ir-ˈ(r)eg-yə-lər \

medical Definition of irregular

1 :lacking perfect symmetry of form :not straight, smooth, even, or regular

irregular teeth

2 a :lacking continuity or regularity of occurrence, activity, or function

irregular breathing

b of a physiological function :failing to occur at regular or normal intervals

irregular menstruation

have your bowels been irregular

c of an individual :failing to defecate at regular or normal intervals

was constipated and very irregular

—

irregularly

adverb

Law Dictionary

irregular

adjective ir·reg·u·lar \ ir-ˈre-gyə-lər \

legal Definition of irregular

:not in accord with laws, rules, procedures, or established custom

—

irregularly

adverb

Learn More about irregular

Thesaurus: All synonyms and antonyms for irregular Spanish Central: Translation of irregular Nglish: Translation of irregular for Spanish speakers Britannica English: Translation of irregular for Arabic speakers

Seen and Heard

What made you want to look up irregular? Please tell us where you read or heard it (including the quote, if possible).

show

irregular

Definition of irregular

irregularly

Read the Latest from M-W

Examples of irregular in a Sentence

Recent Examples of irregular from the Web

Origin and Etymology of irregular

irregular Synonyms

Synonyms

Antonyms

Related Words

Near Antonyms

Synonym Discussion of irregular

irregular

Definition of irregular

Recent Examples of irregular from the Web

First Known Use of irregular

IRREGULAR Defined for English Language Learners

irregular

Definition of irregular for English Language Learners

irregular

Definition of irregular for English Language Learners

IRREGULAR Defined for Kids

irregular

Definition of irregular for Students

irregularly

Medical Dictionary

irregular

medical Definition of irregular

irregularly

Law Dictionary

irregular

legal Definition of irregular

irregularly

Learn More about irregular

Seen and Heard

Love words? Need even more definitions?

Love words? Need even more definitions?

Words at Play

Ask the Editors

Word Games

The History of the Word 'Terrorism'

Trending: McCain: Half-Baked, 'Spurious' Nationalism

17 English Words that Come From Japanese

Forms of Government Quiz

Words of the Year: 1066