anomaly

Etymology

It is partly borrowed from Middle French anomalie (“irregularity”), recorded from 1570, and partly borrowed from Latin anōmalia,^[2] the source the other dictionaries give alone.^{[3][4][5][6][7]} The Latin noun, used by Varro,^[5] meant an irregularity in grammar, and in post-classical Latin also the angular distance of a planet from its perihelion (by 1566).^[2] It is from Ancient Greek ἀνωμαλία (anōmalía, “unevenness, irregularity”), from ἀνώμαλος (anṓmalos, “uneven, irregular”),^[2][3][7][4] formed from ἀν- (an-, “not”) and ὁμαλός (homalós, “even”),^[3][4] which is probably from ὁμός (homós, “same”),^[4][3] from Proto-Indo-European *sem- (“one; as one, together with”).^[3] The Greek noun also meant a deviation from rule in grammar, and in Hellenistic Greek an irregular motion in astronomy.^[2] The OED compares Italian anomalia (1587) and German Anomalie (late 17th century).^[2]

Earliest recorded meaning

Etymonline dates the word to the 1570s, in the sense "unevenness",^[3] and Merriam-Webster and Barnhart to 1571.^[8][4] The OED's first quotation is from 1585, in a translation of P. de La Ramée's Latin grammar, for a word that does not follow the usual rules of inflection.^[2]

Semantic evolution

The word entered English as a technical term of grammar, gunnery and astronomy: in 1591 it was used for the dispart of a cannon, the difference between its radius at the base ring and at the muzzle (a rare sense now lost),^[2] and since 1602 for the angular distance of a planet from its perihelion or aphelion.^[2] The general senses followed: an oddity or anomalous thing from 1631, and irregularity or deviation from the norm from 1648;^[2] Etymonline dates "deviation from the common rule" to the 1660s and "something abnormal" to 1722.^[3] Johnson (1755) defined it as "irregularity; deviation from the common rule".^[9] From 1686, in Boyle, it was used of irregularities in nature, and later sciences made it a term for a measured value that differs from the expected one: in tuning (1694), in meteorology (1853), for the force of gravity (1894) and, in medicine, for an abnormality of the body (1814).^[2]

Timeline

• 1571 – first record, according to Barnhart and Merriam-Webster.^[4][8]
• 1585 – grammar, an irregular form.^[2]
• 1591 – gunnery, the dispart of a cannon (obsolete).^[2]
• 1602 – astronomy, angular distance from the perihelion.^[2]
• 1631 – an oddity, something anomalous.^[2]
• 1648 – irregularity, deviation from the norm.^[2]
• 1686 – an irregularity in a natural system.^[2]
• 1814 – medicine, a bodily abnormality.^[2]
• 1853 – meteorology, temperature anomaly.^[2]
• 1894 – geology, gravity anomaly.^[2]

Meanings

Noun

1. Something that departs from what is usual or expected; an oddity: The cold summer was an anomaly in a decade of heat.^[8][10][2]
2. Deviation from the normal order or type; irregularity.^[10][2]
3. (astronomy) An angle that fixes the position of an orbiting body relative to its perihelion or other apsis, as the true anomaly or eccentric anomaly.^[10][2]
4. (grammar) A word form or construction that does not follow the usual rules, such as an irregular inflection.^[8][2]
5. (physics, geology, meteorology) The difference between a measured value, such as the force of gravity or the mean temperature at a place, and the value expected.^[2][5]
6. (medicine) An abnormality of the structure or function of a part of the body.^[2]

Word family

• anomalistic
• anomalistically
• anomalism
• anomalous
• mean anomaly
• true anomaly

Related words

• same
• homo-

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r s t u v w x y Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d e f Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
5. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
7. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
8. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
9. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
10. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins