conjecture
Americannoun
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conjectures
plural
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the formation or expression of an opinion or theory without sufficient evidence for proof.
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an opinion or theory so formed or expressed; guess; speculation.
- Synonyms:
- hypothesis, theory, supposition, inference, surmise
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Obsolete. the interpretation of signs or omens.
verb (used with object)
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conjectures,
present (3rd person singular)
-
conjectured,
past participle, past
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conjecturing
present participle
verb (used without object)
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conjectures,
present (3rd person singular)
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conjectured,
past participle, past
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conjecturing
present participle
noun
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the formation of conclusions from incomplete evidence; guess
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the inference or conclusion so formed
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obsolete interpretation of occult signs
verb
Synonym Usage
See guess.
Other Word Forms
Derived Forms
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conjecturernoun
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misconjectureverb
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preconjectureverb (used with object)
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conjecturableadjective
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nonconjecturableadjective
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unconjecturableadjective
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unconjecturedadjective
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conjecturablyadverb
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nonconjecturablyadverb
Inflected Forms
Nouns
Participles
Conjugated Forms
Present
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conjecturesimple
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conjecturessimple
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have conjecturedperfect
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has conjecturedperfect
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am conjecturingprogressive
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are conjecturingprogressive
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is conjecturingprogressive
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have been conjecturingperfect progressive
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has been conjecturingperfect progressive
Past
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conjecturedsimple
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had conjecturedperfect
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was conjecturingprogressive
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were conjecturingprogressive
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had been conjecturingperfect progressive
Future
Etymology
Origin of conjecture
First recorded in 1350–1400; (for the noun) Middle English, from Middle French, from Latin conjectūra “inference, reasoning,” from conject(us) “thrown together” (past participle of conicere, conjicere “to throw together, form a conclusion,” from con- con- + -icere, -jicere, combining form of jacere “to throw”) + -ūra -ure; (for the verb) late Middle English conjecturen, from Middle French, from Late Latin conjecturāre, derivative of the noun
Explanation
Can you guess what conjecture means? It's a word to use when you are not sure of something and have to "guess or surmise." You can see how the word conjecture means that you create a theory or opinion about something without basing it in fact because the original definition of conjecture, from Old French, is "interpretation of signs and omens." Since signs and omens are pretty subjective, it makes sense that the word would then move to its current meaning. However, even though it only seems like weather reports are conjectures, they are actually based on evidence!
Vocabulary lists containing conjecture
Narrative of the Life of Frederick Douglass
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Their Eyes Were Watching God
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Grade 12, List 2
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
The first problem we run into is that assessing the economic effects of the wealth tax is an exercise in conjecture.
From Los Angeles Times ● Oct. 16, 2026
It was an eye-catching conjecture: one of the most revered of the Founding Fathers subjecting people held against their will to possibly painful shocks.
From Salon ● Sep. 25, 2026
The rumor mill is active, locals say, and includes conjecture on whether Musk himself might show up.
From The Wall Street Journal ● Aug. 22, 2026
Schnoebelen said that while the speculating on the origins of the statue is all conjecture at this point, she does enjoy the attention the statue has brought to this particular period of art.
From Los Angeles Times ● Aug. 14, 2026
We do not understand human behavior well enough to be sure of the mechanisms underlying these relationships, although we can conjecture.
From "Cosmos" by Carl Sagan
In a year of unthinkable math progress, as increasingly powerful AI systems have cracked conjectures that had long stumped humans, OpenAI published a breakthrough on Tuesday that represents the most significant advance yet.
From The Wall Street Journal ● Sep. 8, 2026
"This unprecedentedly clear signal of the black hole merger known as GW250114 puts to the test some of our most important conjectures about black holes and gravitational waves," Isi said.
From Science Daily ● Dec. 8, 2025
Despite all that, conjectures by laypersons that the illness or death of acquaintances can be traced to the vaccines are legion.
From Los Angeles Times ● Jun. 19, 2024
A lawyer for the New Jersey senator said the justice department claims were "baseless" and "bizarre conjectures".
From BBC ● Jan. 2, 2024
G. W., by contrast, is happy to entrust himself to ‘strong, and shrewd conjectures’.
From "The Invention of Science" by David Wootton
Erdős conjectured that the maximum number of pairs, suggested by a gridlike system, could increase only slightly faster than the number of dots.
From The Wall Street Journal ● Jun. 14, 2026
But, for an elusive conjectured class of materials, physicists have now shown that the surface previously thought to be "featureless" holds an unmistakable signature that could lead to the first definitive observation.
From Science Daily ● Jan. 16, 2024
“Is there a universal basis for selection? Is there a more quantitative formalism underlying this conjectured conceptual equivalence—a formalism rooted in the transfer of information?,” they ask of the world’s disparate phenomena.
From Salon ● Oct. 22, 2023
Francis Guthrie first conjectured the four-color theorem in 1852 when he noticed that the counties of England only needed four colors to properly fill.
From Scientific American ● Jul. 24, 2023
International master George Koltanowski conjectured that Bobby just didn’t trust people and didn’t want to be cheated: “There’s a word for it in German: Verfolgungswahnsinn,” he said.
From "Endgame" by Frank Brady
Simpson homicide trial in 1994, Wecht was a frequent talk show guest, conjecturing on the “Today” show and “Good Morning America” about the significance of blood samples and other evidence.
From Seattle Times ● May 13, 2024
The outlay had some crypto followers conjecturing that he meant to consolidate the industry in his own hands.
From Los Angeles Times ● Nov. 9, 2022
"Rather than conjecturing whether Xi would restrain actions before the party congress, it is more realistic to analyse its daily military activities and make preparations accordingly," the official added.
From Reuters ● Feb. 23, 2022
Even the former commander of U.S. forces in Afghanistan, Gen. Stanley McChrystal, talked about "insurgent math," conjecturing that for every innocent person killed, the U.S. created 10 new enemies.
From Salon ● Sep. 20, 2021
They had a pleasant five minutes conjecturing about how much was in the bank.
From "A Tree Grows in Brooklyn" by Betty Smith
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