irregular

[ ih-reg-yuh-ler ]

adjective

1. without symmetry, even shape, formal arrangement, etc.:

   an irregular pattern.

   Synonyms: unsymmetrical, uneven

2. not characterized by any fixed principle, method, continuity, or rate:

   irregular intervals.

   Synonyms: unsystematic, unmethodical, lawless, eccentric, erratic, capricious, disorderly

3. not conforming to established rules, customs, etiquette, morality, etc.:

   highly irregular behavior.

4. not according to rule, or to the accepted principle, method, course, order, etc.

   Synonyms: unusual, anomalous

5. 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.

6. Military. (formerly, of troops) not belonging to an organized group of the established forces.
7. flawed, damaged, or failing to meet a specific standard of manufacture:

   a sale of irregular shirts.

8. Botany.
   1. not uniform.
   2. (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.
9. deviating or experiencing deviations from a normally regular or cyclic body function, as bowel habits or menstruation.
10. (of a stock or commodity market) of mixed market activity; showing no clear up or down trend.

noun

1. a person or thing that is irregular.
2. Commerce. a product or material that does not meet specifications or standards of the manufacturer, as one having imperfections in its pattern.
3. Military. a soldier or combatant not of a regular military force, as a guerrilla or partisan.

irregular

/ ɪˈrɛɡjʊlə /

adjective

1. lacking uniformity or symmetry; uneven in shape, position, arrangement, etc
2. not occurring at expected or equal intervals

   an irregular pulse

3. differing from the normal or accepted practice or routine
4. not according to established standards of behaviour; unconventional
5. (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
6. of or relating to guerrillas or volunteers not belonging to regular forces

   irregular troops

7. (of flowers) having any of their parts, esp petals, differing in size, shape, etc; asymmetric
8. (of merchandise) not up to the manufacturer's standards or specifications; flawed; imperfect

noun

1. a soldier not in a regular army
2. See second
   often plural imperfect or flawed merchandise Compare second 1

Derived Forms

• irˈregularly, adverb

Other Words From

• ir·regu·lar·ly adverb
• quasi-ir·regu·lar adjective
• quasi-ir·regu·lar·ly adverb

Word History and Origins

Origin of irregular¹

First recorded in 1350–1400; from Late Latin irrēgulāris ( ir- ², regular ); replacing Middle English irreguler, from Middle French

Synonym Study

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).

Example Sentences

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.

From 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.

From 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.

From 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.

From Voice of San Diego

The lumpy shape of Phobos is also evident from its irregular silhouette against the sun.

From Nautilus

Iraq may have been an irregular fight, but it had major moments.

From The Daily Beast

Maybe Mimas is solid, but its core is irregular, like the shape of many asteroids.

From The Daily Beast

Objects more massive than a certain amount are more spherical than not, while punier specimens are lumpy and irregular.

From The Daily Beast

For instance, in active REM sleep, breathing and pulse may be irregular, and small muscular twitches are common.

From The Daily Beast

But irregular Ukrainian troops armed with first-class rifles, mortars, and explosive devices would do Russian troops great damage.

From The Daily Beast

The cantonment was split into two sections by an irregular ravine, or nullah, running east and west.

From Project Gutenberg

They lie either singly or superimposed to form more or less irregular clusters (Fig. 36).

From Project Gutenberg

Sometimes dumb-bells, compact sheaves of fine needles, and irregular rhizome forms are seen (Fig. 40).

From Project Gutenberg

They are usually shorter and more irregular in outline, and more frequently have irregularly broken ends.

From Project Gutenberg

Each contains one irregular nucleus or several small, rounded nuclei.

From Project Gutenberg

Related Words

• capricious
• erratic
• intermittent
• jerky
• sporadic
• uneven
• unreliable