conjugate

Etymology

The adjective is inherited from Middle English conjugat,^[2] borrowed from Latin coniugātus (“yoked together, joined”), the past participle of coniugō (“to yoke together, unite”).^{[3][2][4][5][6]} Barnhart treats the verb as a use of the earlier adjective,^[4] while the OED derives it from the participial stem of the same Latin verb and compares French conjuguer.^[3] The Latin verb is formed from com- (“together”) and iugō (“to join, yoke, marry”),^[3][2][7][8] from iugum (“yoke”),^[3][9][7] from Proto-Indo-European *yeug- (“to join”).^[9][7] Klein also relates it to iungō (“to join”), the source of join.^[8]

Earliest recorded meaning

Joined together, especially in a pair; coupled or connected: 1471, in Ripley's Compound of Alchymy.^[3][4] Dictionary.com dates the adjective to 1425–75,^[10] the Oxford Dictionary of English to the late 15th century.^[6]

Semantic evolution

The grammatical verb, to set out the inflected forms of a verb, appears in 1530 in Palsgrave's Lesclarcissement de la langue francoyse,^[3][4] the year Merriam-Webster Unabridged also gives;^[2] Etymonline places it in the 1520s.^[9] Etymonline quotes the Century Dictionary's explanation: in inflected languages a verb is conjugated by joining inflectional syllables to its root.^[9] The literal verb, to yoke or join together, is recorded only from 1570 and was always rare;^[3] Collins marks the sense "to join in marriage" as obsolete.^[11] The noun for a word derived from the same root as another dates from about 1586,^[2] and Johnson (1755) defined it so, adding that such words usually resemble each other in meaning.^[12] From 1680 the adjective was used in mathematics and physics of two points, lines or quantities in a reciprocal relation, as in conjugate axes and diameters.^[3][5] The 19th century added uses in botany (leaves growing in pairs, 1785), biology (cells united in conjugation, 1843; the verb in Darwin, 1872), grammar (words from one root, 1862), chemistry and medicine (both 1882).^[3]

Timeline

• 1471 – adjective, joined together, coupled.^[3][4]
• 1530 – verb, to inflect a verb, in Palsgrave.^[3][4][2] Etymonline dates it to the 1520s.^[9]
• 1570 – verb, to yoke or join together.^[3]
• c. 1586 – noun, a word with the same derivation as another.^[2]
• 1680 – mathematics, reciprocally related, as of axes or diameters.^[3]
• 1785 – botany, of leaves growing in pairs.^[3]
• 1843 – biology, of cells united in conjugation.^[3]
• 1862 – grammar, of words derived from the same root.^[3]
• 1872 – verb, biology, to unite in conjugation, in Darwin.^[3]
• 1882 – chemistry, conjugate compounds and acids; verb, to combine one compound with another.^[3]
• 1882 – pathology, conjugate deviation of the eyes.^[3]

Meanings

Verb

1. (grammar) To give the inflected forms of a verb in order: The pupils conjugated the French verb chanter on the board.^[11][2][3]
2. (grammar) Of a verb, to be inflected according to a set pattern.^[11]
3. (chemistry) To combine one compound with another so that the product can easily be broken down into them again.^[11][2][3]
4. (biology) To undergo conjugation.^[11][3]
5. To join together; to yoke or couple.^[2][3]

Adjective

1. Joined together, especially in pairs; paired or coupled.^[11][2][3]
2. (mathematics) Related to each other reciprocally, sharing certain features but being opposite or inverse in one, as two complex numbers or two axes.^[2][3][5]
3. (grammar) Of words, derived from the same root.^[3][5]
4. (chemistry) Of an acid and a base, related to each other by the gain or loss of a proton.^[5][3]
5. (botany) Of leaves, growing in pairs.^[3]

Noun

1. A word that has the same derivation as another, and usually a related meaning.^[2][12]
2. (mathematics) A conjugate axis, diameter or complex number.^[2]

Word family

• conjugately
• conjugative
• conjugator
• conjugateness
• conjugably
• misconjugate
• nonconjugate
• Hermitian conjugate

Related words

• conjugal
• conjugation
• yoke
• join
• conjoin
• jugate

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 Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
3. ^ 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 z 27 28 Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
4. ^ a b c d e f Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
5. ^ a b c d e Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
7. ^ a b c The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
8. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
9. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
10. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
11. ^ a b c d e f Collins English Dictionary (2023), Glasgow: HarperCollins
12. ^ 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.