deviation

Etymology

It is inherited from Middle English deviacion,^[2] borrowed from Middle French déviation and directly borrowed from Medieval Latin dēviātiō,^[3][4][5][2] from Latin dēviō (“to turn aside, go out of the way”),^[6][7][4] formed from the phrase dē viā (“off the way”), from dē (“off, away”) and via (“way”).^[7] Etymonline and Dictionary.com go through the Late Latin past participle dēviātus,^[7][5] and the OED, which treats the English word as a noun of action formed on the Latin verb with -ation, notes that the French word is recorded from 1461 but was in the Académie's dictionary only from 1762.^[6]

Earliest recorded meaning

A going astray from the true way; an error: in Usk's Testament of Love (about 1385), which glosses the word as "going out of trewe way".^[2] The Middle English Dictionary also records it in religious texts for the state of humankind between Adam and Christ, the time of deviation.^[2] Etymonline dates the word to the late 14th century,^[7] Dictionary.com to 1375–1425 and Merriam-Webster to the 15th century,^[5][8] while the OED's first quotation is from 1603, in Holland's Plutarch.^[6]

Semantic evolution

The figurative sense, divergence from a course, rule or standard, is in the OED's words the earliest and most frequent one;^[6] Etymonline dates "departure from a standard or rule of conduct" to the 1630s.^[7] The literal sense, turning aside from a path or track, follows in 1646 in Sir Thomas Browne,^[6] and a sense of moral going astray was used from 1625 to 1831.^[6] Johnson (1755) gave "the act of quitting the right way", "variation from established rule" and "offence; obliquity of conduct".^[9] Technical uses followed: the amount of divergence from a straight line or a standard (1675), the error of a ship's compass needle caused by the iron in the ship (1819), a ship's voluntary departure from its intended course in commerce (1809),^[6] and in statistics the amount by which a measurement differs from the mean (1858), with standard deviation from 1894.^[6][7] In 20th-century politics it came to mean departure from a party's line, especially in Communist societies (1931).^[6]

Timeline

• c. 1385 – a going out of the true way, in Usk.^[2]
• 1603 – divergence from a course, rule or standard.^[6]
• 1625 – moral going astray (obsolete by 1831).^[6]
• 1646 – turning aside from a path, deflection.^[6]
• 1755 – Johnson defines it as the act of quitting the right way.^[9]
• 1819 – the deflection of a ship's compass needle.^[6]
• 1858 – in statistics, divergence from the mean.^[6][7]
• 1894 – standard deviation.^[7]
• 1931 – departure from a party's policy.^[6]

Meanings

Noun

1. The act of departing from a usual course, rule or standard, or an instance of it: Any deviation from the safety procedure must be reported.^[8][10][6]
2. A turning aside from a path or route; a deflection.^[8][6]
3. In statistics, the difference between one value in a set and the mean of the set.^[10][6]
4. The error of a compass needle caused by magnetic influences in the ship or aircraft that carries it.^[10][8][6]
5. Departure from the official line of a political party, especially a communist one.^[6][3]

Word family

• deviationism
• deviationist
• nondeviation
• standard deviation

Related words

• deviance
• deviate
• deviant
• devious
• via

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e 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 Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
4. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
5. ^ a b c Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
6. ^ 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
7. ^ a b c d e f g h Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
8. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
9. ^ a b 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