irregular

See also: irregulär

English

Etymology

From Middle English irreguler, from Old French irreguler, from Medieval Latin or Late Latin irrēgulāris, from in- + regularis, equivalent to ir- +‎ regular.

Pronunciation

• (Received Pronunciation) IPA^(key): /ɪˈɹɛɡ.jʊ.lə/

  • Audio (Southern England):

    (file)

• (General American) IPA^(key): /ɪˈɹɛɡ.jə.lɚ/
• (General Australian) IPA^(key): /ɪˈɹeɡ.jə.lə/

• Audio (US):

  (file)

Adjective

irregular (comparative more irregular, superlative most irregular)

1. Nonstandard; not conforming to rules or expectations.
   • 1967, Barbara Sleigh, Jessamy, Sevenoaks, Kent: Bloomsbury, published 1993, →ISBN, page 33:

     ‘ “It would be most irregular Grandpa!” says Miss Cecily frowning and tapping her foot. “Well, we’re a pretty irregular family so that’s neither here nor there,” says the old man, impish like. [...] ’

2. Rough (of a surface).
3. Without symmetry, regularity, or uniformity.
   • 1944, Miles Burton, chapter 5, in The Three Corpse Trick:

     The hovel stood in the centre of what had once been a vegetable garden, but was now a patch of rank weeds. Surrounding this, almost like a zareba, was an irregular ring of gorse and brambles, an unclaimed vestige of the original common.

   • 1980, AA Book of British Villages, Drive Publications Ltd, page 100:

     Near by, where the crystal clear River Llugwy is crossed by a bridge, stands a small and ancient church built of massive, irregular boulders.

   • 2013 January 1, Paul Bartel, Ashli Moore, “Avian Migration: The Ultimate Red-Eye Flight”, in American Scientist, volume 101, number 1, pages 47–48:

     Many of these classic methods are still used, with some modern improvements. For example, with the aid of special microphones and automated sound detection software, ornithologists recently reported […] that pine siskins (Spinus pinus) undergo an irregular, nomadic type of nocturnal migration.

   • 2013 July 19, Ian Sample, “Irregular bedtimes may affect children's brains”, in The Guardian Weekly, volume 189, number 6, page 34:

     Irregular bedtimes may disrupt healthy brain development in young children, according to a study of intelligence and sleeping habits.  ¶ Going to bed at a different time each night affected girls more than boys, but both fared worse on mental tasks than children who had a set bedtime, researchers found.

   • 2019 October, Tony Miles, Philip Sherratt, “EMR kicks off new era”, in Modern Railways, page 58:

     The improvements will be most keenly felt across Lincolnshire, where current irregular service patterns are more a function of operational convenience than passenger demand.

4. (geometry, of a polygon) Not regular; having sides that are not equal or angles that are not equal.
5. (geometry, of a polyhedron) Whose faces are not all regular polygons (or are not equally inclined to each other).
6. (grammar, of a word) Not following the regular or expected patterns of inflection in a given language.

   "Calves", "cacti", and "children" are irregular plurals.

   "To buy" is an irregular English verb: its past simple and past participle tense is "bought".

   I hate learning all the irregular conjugations in French.

Synonyms

• (nonstandard): abnormal, singular; see also Thesaurus:strange
• (rough): coarse, salebrous; see also Thesaurus:rough
• (without uniformity): unstable, unsteady; see also Thesaurus:unsteady
• (not following the regular patterns of inflection): heteroclite

Antonyms

• regular

Derived terms

• irregular galaxy
• irregularist
• irregularity
• irregularization
• irregularize
• irregularly
• irregularness
• irregular prime
• irregular prism
• irregular verb
• irregular warfare
• nonirregular
• on an irregular basis
• regioirregular
• stereoirregular

Translations

non-standard

• Armenian: անկանոն (hy) (ankanon)
• Belarusian: няпра́вільны (njaprávilʹny), нестанда́ртны (njestandártny)
• Bulgarian: непра́вилен (bg) (neprávilen), нередо́вен (bg) (neredóven)
• Catalan: irregular (ca)
• Chinese:

  Mandarin: 無常 / 无常 (zh) (wúcháng)

• Dutch: onregelmatig (nl)
• Esperanto: neregulara
• Finnish: epäsäännöllinen (fi), säännötön (fi)
• French: irrégulier (fr)
• German: irregulär (de), unregelmäßig (de)
• Greek: ακανόνιστος (el) (akanónistos)

  Ancient Greek: ἀνώμαλος (anṓmalos)

• Hindi: अमानक (amānak), अनियमित (hi) (aniymit)
• Ido: neregulala (io)
• Irish: neamhrialta
• Italian: irregolare (it)
• Japanese: 不規則な (ja) (ふきそくな, fukisoku na), 変則的な (ja) (へんそくてきな, hensokuteki ni)
• Latin: inconditus m, irrēgulāris, ēnormis
• Māori: hikuwaru
• Norman: irrédgulyi
• Norwegian:

  Bokmål: irregulær

  Nynorsk: irregulær

• Plautdietsch: onbestendich
• Polish: nieregularny (pl)
• Portuguese: irregular (pt)
• Romanian: iregular, nereglementar, neregulat (ro)
• Russian: непра́вильный (ru) (neprávilʹnyj), нестанда́ртный (ru) (nestandártnyj)
• Spanish: irregular (es)
• Swedish: oregelbunden (sv)
• Turkish:

  Ottoman Turkish: قاعده‌سز (kaʿidesiz)

• Ukrainian: непра́вильний (neprávylʹnyj), нестанда́ртний (nestandártnyj)

in grammar, applied to words

• Arabic: شَاذّ (ar) (šāḏḏ), غَيْر مُنْتَظِم (ḡayr muntaẓim)
• Armenian: անկանոն (hy) (ankanon)
• Belarusian: няпра́вільны (njaprávilʹny)
• Bulgarian: непра́вилен (bg) (neprávilen)
• Catalan: irregular (ca)
• Chinese:

  Mandarin: 不規則 / 不规则 (zh) (bùguīzé)

• Czech: nepravidelný (cs)
• Danish: uregelmæssig
• Dutch: onregelmatig (nl)
• Finnish: epäsäännöllinen (fi), säännötön (fi)
• French: irrégulier (fr)
• German: unregelmäßig (de)
• Greek: ανώμαλος (el) (anómalos)

  Ancient Greek: ἀνώμαλος (anṓmalos)

• Hungarian: rendhagyó (hu)
• Icelandic: óreglulegur (is)
• Irish: neamhrialta, mírialta
• Italian: irregolare (it)
• Japanese: 不規則な (ja) (ふきそくな, fukisoku na)
• Korean: 불규칙하다 (ko) (bulgyuchikhada)
• Latin: anomalus m
• Macedonian: неправилен (nepravilen)
• Norman: irrédgulyi
• Norwegian:

  Bokmål: uregelrett, uregelmessig (no)

  Nynorsk: uregelrett

• Polish: nieregularny (pl)
• Portuguese: irregular (pt)
• Romanian: neregulat (ro)
• Russian: непра́вильный (ru) (neprávilʹnyj)
• Serbo-Croatian:

  Cyrillic: не̏правӣлан

  Latin: nȅpravīlan (sh)

• Slovak: nepravidelný
• Slovene: nepravilen
• Spanish: irregular (es)
• Swedish: oregelbunden (sv)
• Turkish: düzensiz (tr)
• Ukrainian: непра́вильний (neprávylʹnyj)

lacking uniformity

• Armenian: անկանոն (hy) (ankanon)
• Bulgarian: неравноме́рен (bg) (neravnoméren)
• French: irrégulier (fr)
• Greek: ασύμμετρος (el) (asýmmetros)
• Hindi: अनियमित (hi) (aniymit)
• Hungarian: rendszertelen (hu)
• Japanese: 不揃いの (ja) (ふぞろいの, fuzoroi no), 不同の (ja) (ふどうの, fudō no)
• Māori: kōiheihe, tipihori, tipirori, tipitaha, whakarangirua, kōhikohiko, whakahipahipa, karawhiti, kōngunungunu, hikuwaru, karawhiti, tōroherohe
• Norwegian:

  Bokmål: uregelmessig (no), uregelrett

  Nynorsk: uregelmessig, uregelrett

• Portuguese: irregular (pt), desigual (pt), assimétrico (pt)
• Russian: неравноме́рный (ru) (neravnomérnyj)
• Spanish: irregular (es), arrítmico (es)

The translations below need to be checked and inserted above into the appropriate translation tables. See instructions at Wiktionary:Entry layout § Translations.

Translations to be checked

• Woiwurrung: ^{(please verify)} na-boon-tin marr-neen-manee

Noun

irregular (plural irregulars)

1. A soldier who is not a member of an official military force and who may not use regular army tactics.
2. One who does not regularly attend a venue.
   • 2015, Brian Cook, Hands Across The Sea, page 190:

     There's one neighborhood tavern where the regulars and irregulars go after a hard day to unlax and rewind, throw back a few, and just hang out - you know the one.

Derived terms

• Baker Street Irregular

Translations

soldier

• French: irrégulier (fr) m
• Greek: άτακτος (el) m (átaktos)

  Ancient Greek: ἀσύντακτος m (asúntaktos)

• Turkish:

  Ottoman Turkish: لوند (levend)

Catalan

Etymology

Borrowed from Late Latin irrēgulāris.

Pronunciation

• IPA^(key): (Central) [i.rə.ɣuˈlar]
• IPA^(key): (Balearic) [i.rə.ɣuˈla]
• IPA^(key): (Valencia) [i.re.ɣuˈlaɾ]

• Audio (Barcelona):

  (file)

• Rhymes: -aɾ

Adjective

irregular m or f (masculine and feminine plural irregulars)

1. irregular

   Antonym: regular

Derived terms

• irregularment

Related terms

• irregularitat

Further reading

• “irregular”, in Diccionari de la llengua catalana [Dictionary of the Catalan Language] (in Catalan), second edition, Institute of Catalan Studies [Catalan: Institut d'Estudis Catalans], April 2007
• “irregular”, in Gran Diccionari de la Llengua Catalana, Grup Enciclopèdia Catalana, 2026
• “irregular” in Diccionari normatiu valencià, Acadèmia Valenciana de la Llengua.
• “irregular” in Diccionari català-valencià-balear, Antoni Maria Alcover and Francesc de Borja Moll, 1962.

Galician

Etymology

Attested since circa 1300. Borrowed from Late Latin irrēgulāris.

Pronunciation

 

• IPA^(key): /ireɡuˈlaɾ/ [i.re.ɣ̞uˈlaɾ]

• IPA^(key): (standard) /ireɡuˈlaɾ/ [i.re.ɣ̞uˈlaɾ]
• IPA^(key): (gheada) /ireħuˈlaɾ/ [i.re.ħuˈlaɾ]

• Rhymes: -aɾ
• Hyphenation: i‧rre‧gu‧lar

Adjective

irregular m or f (plural irregulares)

1. irregular

   Antonym: regular

Related terms

• irregularidade

References

• Seoane, Ernesto Xosé González; Granja, María Álvarez de la; Agrelo, Ana Isabel Boullón (2006–2022), “yrregular”, in Dicionario de Dicionarios do galego medieval [Dictionary of dictionaries of Medieval Galician] (in Galician), Santiago de Compostela: Instituto da Lingua Galega
• Barreiro, Xavier Varela; Guinovart, Xavier Gómez (2006–2018), “yrregular”, in Corpus Xelmírez: corpus lingüístico da Galicia medieval [Corpus Xelmírez: linguistic corpus of Medieval Galicia] (in Galician), Santiago de Compostela: Instituto da Lingua Galega
• Antón Luís Santamarina Fernández, editor (2006–2013), “irregular”, in Dicionario de Dicionarios da lingua galega [Dictionary of Dictionaries of the Galician language] (in Galician), Santiago de Compostela: Instituto da Lingua Galega
• Antón Luís Santamarina Fernández, Ernesto Xosé González Seoane, María Álvarez de la Granja, editors (2003–2018), “irregular”, in Tesouro informatizado da lingua galega (in Galician), Santiago de Compostela: Instituto da Lingua Galega

Further reading

• “irregular”, in Dicionario da Real Academia Galega (in Galician), A Coruña: Royal Galician Academy, 2012–2026
• “irregular”, in Dicionário Estraviz de galego (in Galician), 2014–2026

Portuguese

Etymology

Borrowed from Late Latin irrēgulāris.

Pronunciation

 

• (Brazil) IPA^(key): /i.ʁe.ɡuˈlaʁ/ [i.he.ɡuˈlah]

• (Brazil) IPA^(key): /i.ʁe.ɡuˈlaʁ/ [i.he.ɡuˈlah]
  • (São Paulo) IPA^(key): /i.ʁe.ɡuˈlaɾ/ [i.he.ɡuˈlaɾ]
  • (Rio de Janeiro) IPA^(key): /i.ʁe.ɡuˈlaʁ/ [i.χe.ɡuˈlaχ]
  • (Caipira) IPA^(key): /i.ʁe.ɡuˈlaɻ/ [i.he.ɡuˈlaɻ]

 

• (Portugal) IPA^(key): /i.ʁɨ.ɡuˈlaɾ/ [i.ʁɨ.ɣuˈlaɾ]

• (Portugal) IPA^(key): /i.ʁɨ.ɡuˈlaɾ/ [i.ʁɨ.ɣuˈlaɾ]
  • (Southern Portugal) IPA^(key): /i.ʁɨ.ɡuˈla.ɾi/ [i.ʁɨ.ɣuˈla.ɾi]

Adjective

irregular m or f (plural irregulares)

1. irregular; nonstandard
2. (grammar) irregular (not following an inflectional paradigm)

Antonyms

• regular

Derived terms

• irregularmente

Related terms

• irregularidade

Further reading

• “irregular”, in Dicionário Priberam da Língua Portuguesa (in Portuguese), Lisbon: Priberam, 2008–2026

Spanish

Etymology

Borrowed from Late Latin irrēgulāris.

Pronunciation

• IPA^(key): /ireɡuˈlaɾ/ [i.re.ɣ̞uˈlaɾ]
• Rhymes: -aɾ
• Syllabification: i‧rre‧gu‧lar

Adjective

irregular m or f (masculine and feminine plural irregulares)

1. irregular, uneven, erratic, haphazard
2. patchy, spotty, jagged, ragged
3. fitful
4. (grammar) (of a verb etc.) irregular

   Antonym: regular

Derived terms

• irregularmente
• verbo irregular

Related terms

• irregularidad
• regular

Further reading

• “irregular”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025