IRREGULAR Synonyms: 265 Similar and Opposite Words

Q: How is the word 'irregular' distinct from other similar adjectives?

The words anomalous and unnatural are common synonyms of irregular . While all three words 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

Q: When would 'anomalous' be a good substitute for 'irregular'?

Although the words anomalous and irregular have much in common, 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

Q: When could 'unnatural' be used to replace 'irregular'?

The meanings of unnatural and irregular largely overlap; however, 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 1 of 2

adjective

i-ˈre-gyə-lər

Definition of irregular

as in abnormal

departing from some accepted standard of what is normal it was a bank customer's slightly irregular behavior that made people suspicious

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Relevance

Antonyms & Near Antonyms

as in sporadic

lacking in steadiness or regularity of occurrence irregular mail delivery to the island

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as in uneven

not having a level or smooth surface although the moon looks smooth from here, it actually has a very bumpy and irregular surface

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as in informal

not rigidly following established form, custom, or rules the request is irregular, but I'll allow it

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as in changing

not staying constant irregular gusts of wind

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Antonyms & Near Antonyms

irregular

2 of 2

noun

as in guerrilla

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Dissimilar Words

Synonym Chooser

How is the word irregular distinct from other similar adjectives?

The words anomalous and unnatural are common synonyms of irregular. While all three words 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

When would anomalous be a good substitute for irregular?

Although the words anomalous and irregular have much in common, 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

When could unnatural be used to replace irregular?

The meanings of unnatural and irregular largely overlap; however, 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

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

Recent Examples of irregular

Adjective

As reported by Dealabs, the tracker may also be able to notify wearers about potential atrial fibrillation and irregular heart rhythms. — Emma Roth, The Verge, 9 Oct. 2026 Since 1972, timekeepers have added 27 positive leap seconds to UTC, at very irregular intervals. — Vahe Peroomian, The Conversation, 8 Oct. 2026

Noun

As fighting raged in 1948 between Arab armies, Palestinian irregulars and Zionist forces, Mariam and her family fled to a Palestinian farming village, Umm al-Fahem. — Isabel Kershner, BostonGlobe.com, 22 July 2023 As volunteer companies were raised to drive out the Mexican forces — who were occupying their own country — some of the irregulars were joined by free black men. — Paula Allen, ExpressNews.com, 15 Feb. 2020 See All Example Sentences for irregular

Recent Examples of Synonyms for irregular

Adjective

According to MedlinePlus, normal pressure hydrocephalus is an abnormal or excessive buildup of cerebrospinal fluid around the brain, which can impact brain function, cause walking or gait changes, or incontinence.

— ABC News, ABC News, 15 Oct. 2026
About one in 10 screening mammograms come back abnormal, but roughly 90% of those findings turn out to be benign.

— Samantha Agate, Kansas City Star, 14 Oct. 2026

Definition of abnormal

Adjective

Only some regional operators have continued sporadic services, generally using smaller feeder vessels.

— Lee Ying Shan, CNBC, 16 Oct. 2026
That said, devolving tropical storms can pack a punch with sporadic gusts and showers as the energy that was formerly bundled in the storm’s center releases outward.

— Sean Macaday, Sacbee.com, 8 Oct. 2026

Definition of sporadic

Adjective

Rising case rates in women under 50, new federal rules on breast density notification and the uneven rollout of 3D mammography are reshaping when and how women get screened.

— Samantha Agate, Miami Herald, 16 Oct. 2026
Grass, uneven ground, tiny puddles, and random objects can become major obstacles when the machine is barely taller than them.

— New Atlas, New Atlas, 16 Oct. 2026

Definition of uneven

Adjective

Filmmaker Ava DuVernay chose Milton Rogovin’s informal, untitled portrait of a beautiful young Buffalo woman from his East Side, 1961-63 collection.

— The Week US, TheWeek, 13 Oct. 2026
Second, the agency can issue formal or informal warning letters threatening consequences if a violation is not remedied.

— Todd Spangler, Variety, 12 Oct. 2026

Definition of informal

Noun

The indictment also describes the detention of a Venezuelan military officer in 2013 who was transported to a camp controlled by Colombia’s FARC guerrilla organization.

— Antonio María Delgado, Miami Herald, 15 Oct. 2026
The next day, the Colombian Army stormed the Palace and retook it, resulting in the deaths and disappearances of at least 94 people, including justices, guerrilla members, civilians and military personnel.

— Anna Marie de la Fuente, Variety, 10 Oct. 2026

Definition of guerrilla

Adjective

That amounts to unchecked growth resulting in relatively dense stands, which are unnatural for this part of the country — despite becoming a familiar sight to Coloradans over the last few decades.

— John Wenzel, Denver Post, 7 Oct. 2026
The California Department of Public Health said animals with rabies will often have strange or unnatural behavior.

— Nicole Buss, Sacbee.com, 4 Oct. 2026

Definition of unnatural

Adjective

With the Patriots and Bills accounting for four games on the schedule, the Jets can’t keep treating divisional victories as occasional breakthroughs.

— Antwan Staley, New York Daily News, 18 Oct. 2026
For most of human history, our Sun’s occasional tantrums have been of little concern to those of us living on Earth’s surface.

— Mike McRae October 15, New Atlas, 16 Oct. 2026

Definition of occasional

Cite this Entry

Style

“Irregular.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/irregular. Accessed 20 Oct. 2026.

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Synonyms of irregular

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Synonyms of irregular

adjective

noun

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