- 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.
- not uniform.
- (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.
Origin of irregular
SynonymsSee more synonyms on Thesaurus.com
1. unsymmetrical, uneven. 2. unmethodical, unsystematic; disorderly, capricious, erratic, eccentric, lawless. 4. anomalous, unusual. Irregular, abnormal, exceptional imply a deviation from the regular, the normal, the ordinary, or the usual. Irregular, not according to rule, refers to any deviation, as in form, arrangement, action, and the like; it may imply such deviation as a mere fact, or as regrettable, or even censurable. Abnormal means a deviation from the common rule, often implying that this results in an aberrant or regrettably strange form or nature of a thing: abnormal lack of emotion; A two-headed calf is abnormal. Exceptional means out of the ordinary or unusual; it may refer merely to the rarity of occurrence, or to the superiority of quality: an exceptional case; an exceptional mind. Because of the stigma of abnormal, exceptional is today frequently substituted for it in contexts where such a euphemism may be thought to be appropriate: a school for exceptional children (children who are abnormal in behavior, mental capacity, or the like).
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for irregular
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
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
October 17, 2014
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
But Mr. Paine assured her that letters were likely to be irregular, and there was no ground for alarm.Brave and Bold
The advance may be irregular but it is advance; and all advance is advance toward Him.The Conquest of Fear
He was furious at this supposition that she would continue in her irregular practices.Within the Law
The enemy, surprised, opened an irregular and ineffective fire.The Story of the Malakand Field Force
Sir Winston S. Churchill
I design it an irregular ode for General Washington's birth-day.The Letters of Robert Burns
- lacking uniformity or symmetry; uneven in shape, position, arrangement, etc
- not occurring at expected or equal intervalsan 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 forcesirregular 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 merchandiseCompare second 1 (def. 15)
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
Word Origin and History for irregular
"a soldier not of the regular army," 1747, from irregular (adj.).
Online Etymology Dictionary, © 2010 Douglas Harper
- Not straight, uniform, or symmetrical, as facial features.
- Of uneven rate, occurrence, or duration, as a heartbeat.
- Deviating from a type; atypical.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.