without symmetry, even shape, formal arrangement, etc.: an irregular pattern.
not characterized by any fixed principle, method, continuity, or rate: irregular intervals.
not conforming to established rules, customs, etiquette, morality, etc.: highly irregular behavior.
not according to rule, or to the accepted principle, method, course, order, etc.
Grammar. not conforming to the prevalent pattern or patterns of formation, inflection, construction, etc., of a language; having a rule descriptive of a very small number of items: The English verbs “keep” and “see” are irregular in their inflections.
Military. (formerly, of troops) not belonging to an organized group of the established forces.
flawed, damaged, or failing to meet a specific standard of manufacture: a sale of irregular shirts.
(of a flower) having the members of some or all of its floral circles or whorls differing from one another in size or shape, or extent of union.
deviating or experiencing deviations from a normally regular or cyclic body function, as bowel habits or menstruation.
(of a stock or commodity market) of mixed market activity; showing no clear up or down trend.
a person or thing that is irregular.
Commerce. a product or material that does not meet specifications or standards of the manufacturer, as one having imperfections in its pattern.
Military. a soldier or combatant not of a regular military force, as a guerrilla or partisan.
- ir·reg·u·lar·ly, adverb
- qua·si-ir·reg·u·lar, adjective
- qua·si-ir·reg·u·lar·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use irregular in a sentence
Further, the most frequently used words in English — words that appear often, even in simple texts, and thus that children cannot avoid — have a high percentage of ambiguous or irregular letter-to-sound spellings.Is there really a ‘science of reading’ that tells us exactly how to teach kids to read? | Valerie Strauss | January 26, 2021 | Washington Post
Pomp flirted with camp, and familiar words unfolded at irregular rhythms, and our eyes weren’t allowed to glaze over, and neither were our ears.Our national anthem ends with a question. Lady Gaga answered it as best she could. | Chris Richards | January 20, 2021 | Washington Post
The irregular finances were first revealed in September 2018 when VOSD’s Will Huntberry found the district had suddenly come up more than $30 million short in its budget.Morning Report: City Stops Paying Rent on 101 Ash St. | Voice of San Diego | September 2, 2020 | Voice of San Diego
The district’s irregular finances first came to light publically in September 2018, when Voice of San Diego revealed the district had suddenly come up more than $30 million short in its budget.
The lumpy shape of Phobos is also evident from its irregular silhouette against the sun.These Images Expose the Dark Side of the Solar System - Issue 89: The Dark Side | Corey S. Powell | August 26, 2020 | Nautilus
Iraq may have been an irregular fight, but it had major moments.Pentagon Doesn’t Know How Many People It’s Killed in the ISIS War | Nancy A. Youssef | January 7, 2015 | THE DAILY BEAST
Maybe Mimas is solid, but its core is irregular, like the shape of many asteroids.
Objects more massive than a certain amount are more spherical than not, while punier specimens are lumpy and irregular.
For instance, in active REM sleep, breathing and pulse may be irregular, and small muscular twitches are common.The Tracker That Might Actually Help You Sleep Better | DailyBurn | October 17, 2014 | THE DAILY BEAST
But irregular Ukrainian troops armed with first-class rifles, mortars, and explosive devices would do Russian troops great damage.Obama Must Show He’ll Use Military Means to Deter Russia in Ukraine | Leslie H. Gelb | March 30, 2014 | THE DAILY BEAST
The cantonment was split into two sections by an irregular ravine, or nullah, running east and west.The Red Year | Louis Tracy
They lie either singly or superimposed to form more or less irregular clusters (Fig. 36).
Sometimes dumb-bells, compact sheaves of fine needles, and irregular rhizome forms are seen (Fig. 40).
They are usually shorter and more irregular in outline, and more frequently have irregularly broken ends.
Each contains one irregular nucleus or several small, rounded nuclei.
British Dictionary definitions for irregular
lacking uniformity or symmetry; uneven in shape, position, arrangement, etc
not occurring at expected or equal intervals: an irregular pulse
differing from the normal or accepted practice or routine
not according to established standards of behaviour; unconventional
(of the formation, inflections, or derivations of a word) not following the usual pattern of formation in a language, as English plurals ending other than in -s or -es
of or relating to guerrillas or volunteers not belonging to regular forces: irregular troops
(of flowers) having any of their parts, esp petals, differing in size, shape, etc; asymmetric
US (of merchandise) not up to the manufacturer's standards or specifications; flawed; imperfect
a soldier not in a regular army
(often plural) US imperfect or flawed merchandise: Compare second 1 (def. 15)
- irregularly, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012