conjecture

Etymology

It is borrowed from Old French conjecture (“surmise, guess”) or directly borrowed from Latin coniectūra (“conclusion, interpretation, guess”),^{[2][3][4][5][6]} literally "a casting together" of facts,^[2][4] from coniectus, the past participle of coniciō (“to throw together; to infer”),^[2][7][8][9] formed from com- (“together”) and iaciō (“to throw”).^{[2][7][10][11]} Etymonline and the American Heritage Dictionary trace the verb to Proto-Indo-European *yeh₁- (“to throw, impel”).^[2][7] The English verb is from Old French conjecturer, itself formed from the French noun.^[3][8][4] Middle English also had the parallel forms conjecte (noun) and conjecten (verb).^[2][4]

Earliest recorded meaning

The interpretation of signs, dreams and omens; divination, or a forecast drawn from omens: about 1384, in the early version of the Wycliffite Bible.^[3][4][2]

Semantic evolution

Ayto explains the development as facts being "thrown together" in the mind and a provisional conclusion drawn from them.^[10] By about 1386, in Chaucer's Clerk's Tale, the noun meant a conclusion drawn from appearances,^[3] and Barnhart finds the general sense of a guess or surmise in the Canterbury Tales about 1395.^[4] An opinion offered on insufficient evidence is recorded from before 1527,^[3][2] and the formation of such opinions, guesswork, from 1535;^[3][2] the old sense of divining from omens lasted until 1697.^[3] Hoad likewise dates the divining sense to the 14th century and the modern one to the 16th.^[5] Of the parallel forms, conjecten could mean to plot or scheme as well as to suppose.^[4] Conjecte disappeared in the 1500s, and in the 1600s conjecture replaced conjecten.^[4] Johnson (1755) defined the noun as "guess; imperfect knowledge".^[12] In textual criticism a conjecture is a proposed reading not found in any manuscript.^[3]

Timeline

• c. 1384 – the interpretation of signs or omens (obsolete by 1697).^[3][4]
• c. 1386 – a conclusion drawn from appearances (obsolete).^[3]
• c. 1395 – a guess or surmise.^[4]
• before 1425 – verb, coniecturen, to infer from signs and omens.^[4]
• before 1527 – an opinion offered on insufficient evidence.^[3][2]
• 1530 – verb, to form an opinion on insufficient grounds, to guess.^[3]
• 1535 – the forming of opinions on insufficient grounds; guesswork.^[3][2]

Meanings

Noun

1. The forming of an opinion or conclusion from incomplete evidence; guesswork: The cause of the fire remains a matter of conjecture.^[13][8][3]
2. An opinion or conclusion formed in this way; a guess or supposition.^[13][3]
3. (obsolete, 1384–1697) The interpretation of signs or omens.^[13][8][3]

Verb

1. To form an opinion about something, or arrive at it, from incomplete evidence; to surmise: Historians have conjectured that the letter was never sent.^[13][8][3]
2. To make a guess or guesses.^[8][3]

Word family

• conjecturable
• conjecturably
• conjecturer
• misconjecture
• unconjectured

Related words

• conjectural
• jet
• jettison
• jetty
• abject
• inject
• project

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
3. ^ a b c d e f g h i j k l m n o p q r Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
4. ^ a b c d e f g h i j k Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
5. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
6. ^ 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 c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
9. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
10. ^ a b Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
11. ^ Skeat, Walter W. (1911), A Concise Etymological Dictionary of the English Language, new ed., Oxford: Clarendon Press
12. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
13. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins