inversion

Etymology

It is borrowed from Latin inversiō (“reversal, transposition”),^{[2][3][4][5][6][7]} a noun of action from inversus, the past participle of invertō (“to turn upside down, turn about”),^[3][4][7][5] which is formed from in- and vertō (“to turn”).^[2] In classical Latin the noun was used in rhetoric for the reversal of the order of words and for saying the opposite of what is meant, as in irony; several of its senses were modelled on Ancient Greek ἀναστροφή (anastrophḗ).^[2] The OED compares Anglo-Norman inversion, used in medicine in the 13th century, and French inversion (from 1529), as well as Spanish inversión and Italian inversione.^[2] Johnson gave the word as French and Latin.^[8]

Earliest recorded meaning

A rhetorical figure in which an opponent's argument is turned against him: 1532, in L. Cox's Art or Crafte of Rhetoryke; this sense was obsolete by the early 19th century.^[2][5] The Oxford Dictionary of English likewise dates the word to the mid 16th century in this rhetorical sense.^[9]

Semantic evolution

From the rhetorical term the word widened in 1546 to any reversal of direction, order or relationship,^[2] which Etymonline dates to the 1550s as "act of inverting" and to the 1590s as "state of being inverted".^[3] From 1583 it named the reversal of the usual order of words in a sentence,^[2][5] and its use in grammar dates from 1842.^[2] It then entered many technical fields: military drill (1627), mathematics (1645), music, where the notes of a chord are moved to another octave (1664), and chemistry, of the reversal of the optical rotation of sugar.^[2][5] In late 19th-century psychology it meant homosexuality, short for sexual inversion (1895), and later identification with the opposite sex (1958);^[3] the OED compares the earlier French phrase inversion du sens génital (1882) and its German model Verkehrung der Geschlechtsempfindung (1870).^[2] The meteorological sense dates from 1902.^[3] Johnson (1755) defined it as a change of order or time, "so as that the last is first, and first last".^[8]

Timeline

• 1532 – rhetoric, turning an opponent's argument against him (now obsolete).^[2]
• 1546 – reversal or transposition of direction, order or relationship.^[2] Etymonline dates the sense to the 1550s.^[3]
• 1583 – reversal of the normal order of words.^[2]
• 1627 – military, a drill movement turning a rank into a file.^[2][5]
• 1645 – mathematics, the reversal of a ratio.^[2]
• 1664 – music, the shifting of the notes of a chord into another octave.^[2]
• 1895 – psychology, homosexuality.^[3]
• 1902 – meteorology.^[3]

Meanings

Noun

1. The act of inverting, or the state of being inverted; a turning upside down or inside out.^[10][7]
2. A reversal of position, order, sequence or relationship: The new law brought an inversion of the old roles of landlord and tenant.^[10][7][5]
3. (rhetoric, grammar) The reversal of the normal order of words, as in "Gone are the days"; anastrophe.^[10][5][2]
4. (music) The rearrangement of the notes of a chord or interval, or the turning of a melody upside down, so that rising intervals fall and falling ones rise.^[5][2]
5. (mathematics) The reversal of a ratio; also a transformation of a figure about a fixed point, or the finding of a function from its transform.^[5][2]
6. (chemistry) The conversion of sucrose by hydrolysis into glucose and fructose, which reverses the direction of optical rotation.^[10][5]
7. (medicine) The turning of an organ partly or wholly inside out.^[7]
8. (geology) A folding back of rock strata upon themselves, so that their order seems reversed.^[7]
9. (obsolete, 1532–1808) In rhetoric, the turning of an opponent's argument against him.^[2][5]

Word family

• inversion therapy
• population inversion
• temperature inversion

Related words

• invert
• inverse
• convert
• version

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 Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g h Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
5. ^ a b c d e f g h i j k l Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
8. ^ 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.
9. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
10. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins