irregular

/ɪˈɹɛɡ.jʊ.lə/

//ɪˈɹɛɡ.jʊ.lə// adj

By · According to Wiktionary data (CC BY-SA) ·

"irregular" is a 9-letter English headword indexed on PlainSpell.

The verdict

“irregular” is a moderately-common English word, ranked #11,238 in English word frequency and used as an adjective.

#11,238
frequency rank, English
9
letters
11
tracked misspellings
1
confusable pair

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Nonstandard; not conforming to rules or expectations.

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

irregular vs irregularly
82% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for irregular
PropertyValue
Headwordirregular
LanguageEnglish
Part of speechAdjective
IPA/ɪˈɹɛɡ.jʊ.lə/
Letters9
Frequency rank#11,238
Misspellings tracked11
Confusable pairs1
SourceWiktionary (kaikki.org)

Where “irregular” sits in English frequency

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right). irregular lands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

Spelling & Dictionary Insight

The English entry for irregular is 9 letters long, classified as an adjective, and transcribed in the International Phonetic Alphabet as /ɪˈɹɛɡ.jʊ.lə/. Corpus data places it at rank #11,238 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 6 distinct senses for this headword, so context determines which meaning a reader should apply.

Our generated misspelling index lists 11 likely wrong-spelling variants for irregular, with forms such as "iregular", "irergular", and "irreggular". Each variant is a distinct typo pattern an edit-distance generator flags, typically a doubled-consonant error, a silent-letter drop, or a vowel substitution. It also participates in 1 confusable-pair relationship, "irregularly", a pairing that trips writers up because the two words share enough sound or shape to blur together.

Etymologically, the entry records: From Middle English irreguler, from Old French irreguler, from Medieval Latin or Late Latin irrēgulāris, from in- + regularis, equivalent to ir- + regular. The correct English form is irregular, spelled I-R-R-E-G-U-L-A-R.

Definition

  1. 1
    Nonstandard; not conforming to rules or expectations.
  2. 2
    Rough (of a surface).
  3. 3
    Without symmetry, regularity, or uniformity.
  4. 4
    Not regular; having sides that are not equal or angles that are not equal.
  5. 5
    Whose faces are not all regular polygons (or are not equally inclined to each other).
  6. 6
    Not following the regular or expected patterns of inflection in a given language.

Etymology

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

Synonyms

abnormalsingularstrangecoarsesalebrousroughunstableunsteadyheteroclite

Antonyms

regular

This word in other languages

irregular(Español)irrégulier(Français)irregulär(Deutsch)irregular(Português)

Common misspellings

Also misspelled as: iregular,irergular,irreggular,irregluar,irregualr,irregularr,irregullar,irregulra,irreuglar,irrgeular,riregular

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of irregular - expressed in single-character edits (insert, delete, or swap one letter). Bigger bars stand out at a glance; a one-edit slip is the hardest to catch.

iregular1irergular2irreggular1irregluar2irregualr2irregularr1irregullar1irregulra2
Edit distance from "irregular"

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "irregular"?
"irregular" is spelled I-R-R-E-G-U-L-A-R. The IPA pronunciation is /ɪˈɹɛɡ.jʊ.lə/.
What does "irregular" mean?
As an adjective, "irregular" means: Nonstandard; not conforming to rules or expectations.
What words are commonly confused with "irregular"?
"irregular" is commonly confused with "irregularly". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "irregular"?
The IPA (International Phonetic Alphabet) transcription for "irregular" is /ɪˈɹɛɡ.jʊ.lə/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "irregular"?
From Middle English irreguler, from Old French irreguler, from Medieval Latin or Late Latin irrēgulāris, from in- + regularis, equivalent to ir- + regular. See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Using “irregular”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is I-R-R-E-G-U-L-A-R - every other letter order is a misspelling in standard orthography.
  • Say it as /ɪˈɹɛɡ.jʊ.lə/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Don't mix it up with “irregularly” - see the side-by-side comparison. irregular vs irregularly
  • Browse more English words and confusable pairs in the same reference. English words
Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list FrequencyWords open word-frequency list