irregular

Etymology

It is inherited from Middle English irreguler,^[2][3][4] borrowed from Old French irreguler (“irregular; incapable, incompetent”),^[5][6][7][8] now irrégulier,^[6][3] from Medieval Latin irrēgulāris (“not regular”),^[5][6][9] which Barnhart and Dictionary.com place in Late Latin.^[8][10] It is formed from ir-, the assimilated form of in- (“not”), and rēgulāris (“having rules, pertaining to rules”),^[6][8][5] the source of regular.^[6][8] The OED cites the Old French word from the 13th century;^[5][6] in Anglo-Norman the word, meaning disqualified from ordination or from clerical office, is recorded from 1267.^[11] Dictionary.com takes the modern English form as a borrowing from Late Latin that replaced the Middle English one.^[10]

Earliest recorded meaning

In the language of the Church, not in conformity with the rule of the Church or of a religious order, and so disqualified from ordination or from clerical office: c. 1380, in Wyclif;^[5] Barnhart and the Middle English Dictionary have it about 1390 in Chaucer's Parson's Tale, of a simonist priest.^[8][2][12]

Semantic evolution

Of people, the word came to mean not obedient to rule, law or moral principle, lawless or disorderly, from 1395.^[5] The general sense, of things not in conformity with rule or with what is usual, is recorded from 1483;^[5][6] that of not being symmetrical or evenly shaped, from 1584;^[5][6] and that of happening at unequal intervals, from 1608.^[5] Technical uses followed: in grammar, of words not inflected in the usual way, from 1611, in Cotgrave;^[5] in mathematics from 1700;^[5] in botany and zoology from 1785;^[5] and of variable stars from 1797.^[6] Johnson (1755) defined it as "deviating from rule, custom, or nature".^[13] The noun, someone who does not belong to a regular body or follow its rules, dates from the 1610s,^[6] and its main modern sense, a soldier who is not part of a regular army, from 1747;^[6] the OED records the adjective of such troops from 1856.^[5] Etymonline quotes the Century Dictionary's remark that the word states only a departure from rule, yet is sometimes used in a sinister sense, as a euphemism for something worse.^[6]

Timeline

• c. 1380 – not in conformity with the rule of the Church; disqualified for ordination.^[5]
• c. 1390 – in Chaucer's Parson's Tale.^[8][2]
• 1395 – of people, lawless, disorderly.^[5]
• 1483 – of things, contrary to rule, not normal.^[5][6]
• 1584 – not symmetrical; uneven in shape or arrangement.^[5]
• 1608 – occurring at unequal intervals.^[5]
• 1611 – grammar, not inflected in the usual way.^[5]
• 1610s – noun, one not belonging to a regular body.^[6]
• 1747 – noun, a soldier not of the regular army.^[6]
• 1797 – of variable stars.^[6]
• 1856 – of troops not in the regular army.^[5]

Modern meaning

Adjective

1. Not even or balanced in shape or arrangement; lacking symmetry: an irregular coastline.
2. Not happening at regular or equal intervals: an irregular heartbeat.
3. Not in keeping with accepted rules, customs or moral principles; improper: irregular payments to an official.
4. (grammar) Not following the usual pattern of inflection or formation, as went for the past of go.
5. (military) Of troops, not belonging to a country's regular army.
6. (botany) Of a flower, having petals or other parts of different shapes or sizes.
7. (Roman Catholic Church) Barred by an impediment from receiving or exercising holy orders.

Noun

1. A soldier who is not a member of a regular force, such as a guerrilla; usually in the plural.
2. irregulars: goods with flaws, sold more cheaply than standard ones.

Word family

• irregularly
• irregularity
• irregular galaxy

Related words

• regular
• rule
• regulate

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c Kurath, Hans; Kuhn, Sherman M.; Lewis, Robert E., eds. (1952–2001), Middle English Dictionary, Ann Arbor: University of Michigan Press; online edition ed. Frances McSparran et al. (2000–2018)
3. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
4. ^ Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ a b c d e f g h i j k l m n o p q r s t Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
6. ^ a b c d e f g h i j k l m n o p Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
7. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
8. ^ a b c d e f Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
9. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
10. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
11. ^ Anglo-Norman Dictionary (AND2), Aberystwyth University, anglo-norman.net (2nd ed., 2005–)
12. ^ Benson, Larry D., Glossarial Concordance to Middle English (Chaucer, Gower), Johns Hopkins University, github.com/jhu-digital-manuscripts/gcme
13. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.