conjecture

1 of 2

noun

con·​jec·​ture kən-ˈjek-chər 

1

a

: inference formed without proof or sufficient evidence

b

: a conclusion deduced by surmise or guesswork

The criminal's motive remains a matter of conjecture.

c

: a proposition (as in mathematics) before it has been proved or disproved

2

obsolete

a

: interpretation of omens

b

: supposition

conjecture

2 of 2

verb

conjectured; conjecturing kən-ˈjek-chə-riŋ 

-ˈjek-shriŋ

transitive verb

1

: to arrive at or deduce by surmise or guesswork : guess

scientists conjecturing that a disease is caused by a defective gene

2

: to make conjectures as to

conjecture the meaning of a statement

intransitive verb

: to form conjectures

conjecturer

kən-ˈjek-chər-ər 

noun

Did you know?

Conjecturing—forming an idea or opinion with some amount of guesswork—usually involves more than simply throwing ideas at the wall and seeing what sticks, but that’s the gist, and with good etymological reason: conjecture comes ultimately from the Latin verb conicere, which means, literally, “to throw together.” To conjecture is to make an educated guess rather than a stab in the dark; it involves piecing together bits of information to come to a plausible conclusion, as in “scientists conjecturing about the cause of the disease.” As such, conjecture tends to show up in formal contexts rather than informal ones, though we reckon one could conjecture if their spaghetti is perfectly cooked based on the amount of time it has been boiling, and on what has worked in the past. (Nota bene: throwing it at the wall doesn’t work!)

Synonyms

Noun

• guess
• shot
• supposition
• surmise

Verb

• calculate
• call
• estimate
• figure
• gauge
• gage
• guess
• judge
• make
• place
• put
• reckon
• suppose

Examples of conjecture in a Sentence

Noun

Whether Columbus brought syphilis to the New World—or to the Old World—has been the subject of conjecture for at least 500 years. —Carl Zimmer, Science, 11 May 2001

… their voices rose in a chorus of conjecture and alarm, repeating the selfsame remark: "What is she going to do? I mean, is Betty going to faint?" —Edna O'Brien, New Yorker, 1 Jan. 1990

The reason why the French with superior man-power and American resources were doing so poorly was not beyond all conjecture. —Barbara W. Tuchman, The March of Folly, 1984

Peculiar features of early maps, which may have been nothing but a draftsman's whimsy, have inspired pages of vain conjecture. —Samuel Eliot Morison, The European Discovery of America, 1971

The biography includes conjectures about the writer's earliest ambitions.

a conjecture about the extent of the injury

Most of the book is conjecture, not fact.

Verb

It is fashionable now to conjecture that the Big Bang was caused by a random quantum fluctuation in a vacuum devoid of space and time. —Martin Gardner, Skeptical Inquirer, November/December 1998

… their traces left for future archaeologists to rediscover and perhaps to wonder or conjecture over. —Jane Jacobs, Cities and the Wealth of Nations, 1984

I am anxious to conjecture beforehand what may be expected from the sowing turneps [sic] in jaded ground, how much from the acre, & how large they will be? —Thomas Jefferson, letter, 29 Dec. 1794

Some have conjectured that the distant planet could sustain life.

We only conjecture about his motives.

Recent Examples on the Web

Noun

However, careful scientific examination has proved both those conjectures wrong. —Paul Smaglik, Discover Magazine, 5 Nov. 2024

What happened after that is conjecture mixed with logic and the findings of a United States Department of Justice investigation. —Tracy Scott Forson, Smithsonian Magazine, 4 Nov. 2024

Verb

Zeilberger and the mathematician Mihai Nica (opens a new tab) have conjectured that just knowing the second and third moments is enough to determine who wins more games. —Erica Klarreich, Quanta Magazine, 29 Aug. 2024

Riemann conjectured that all the other zeros of the function, called nontrivial zeros, have a real part of 1/2, and so are located on this vertical line. —Jordana Cepelewicz, WIRED, 4 Aug. 2024

Word History

Etymology

Noun and Verb

Middle English, from Middle French or Latin; Middle French, from Latin conjectura, from conjectus, past participle of conicere, literally, to throw together, from com- + jacere to throw — more at jet

First Known Use

Noun

14th century, in the meaning defined at sense 2

Verb

15th century, in the meaning defined at transitive sense 1

Phrases Containing conjecture

• a matter of conjecture

Podcast

Get Word of the Day delivered to your inbox!

Kids Definition

conjecture

1 of 2 noun

con·​jec·​ture kən-ˈjek-chər 

: an opinion or judgment based on little or no evidence

conjecture

2 of 2 verb

conjectured; conjecturing

-ˈjek-chə-riŋ,

-ˈjek-shriŋ

: guess sense 1

conjecturer

-ˈjek-chər-ər 

noun