conjecture

American  

[kuhn-jek-cher] / kənˈdʒɛk tʃər /

noun

1. the formation or expression of an opinion or theory without sufficient evidence for proof.

2. an opinion or theory so formed or expressed; guess; speculation.

   Synonyms:

   hypothesis, theory, supposition, inference, surmise

3. Obsolete. the interpretation of signs or omens.

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verb (used with object)

conjectured, conjecturing

1. to conclude or suppose from grounds or evidence insufficient to ensure reliability.

   Synonyms:

   presume, suppose, surmise

verb (used without object)

conjectured, conjecturing

1. to form conjectures.

conjecture British  

/ kənˈdʒɛktʃə /

noun

1. the formation of conclusions from incomplete evidence; guess

2. the inference or conclusion so formed

3. obsolete interpretation of occult signs

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verb

1. to infer or arrive at (an opinion, conclusion, etc) from incomplete evidence

Related Words

See guess.

Other Word Forms

• conjecturable
  adjective
• conjecturably
  adverb
• conjecturer
  noun
• misconjecture
  verb
• nonconjecturable
  adjective
• nonconjecturably
  adverb
• preconjecture
  verb (used with object)
• unconjecturable
  adjective
• unconjectured
  adjective

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!

Example Sentences

Conjecture about ChatGPT’s apparent addiction to the em dash has been percolating online for months.

From Salon • Jun. 11, 2025

“People are actively trying to build systems that self-improve,” said Connor Leahy, the founder of Conjecture, a company that says it wants to align AI technologies with human values.

From Seattle Times • Jun. 19, 2023

Conjecture is the Patriots had to scramble when Devin Lloyd was snapped up just before they were picking.

From Los Angeles Times • Apr. 30, 2022

The Krauthammer Conjecture: In sports, the joy of winning is dwarfed by the pain of losing.

From Washington Post • Jun. 22, 2018

Conjecture has been at a loss to ascertain the means by which such solid masses could have been conveyed, and placed in so elevated a situation without the aid of machinery.

From Curiosities of Great Britain: England and Wales Delineated Vol.1-11 Historical, Entertaining & Commercial; Alphabetically Arranged. 11 Volume set. by Dugdale, Thomas Cantrell

Related Words

• guesswork
• hunch
• hypothesis
• inference
• supposition