the formation or expression of an opinion or theory without sufficient evidence for proof.
an opinion or theory so formed or expressed; guess; speculation.
Obsolete. the interpretation of signs or omens.

verb (used with object), con·jec·tured, con·jec·tur·ing.

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

verb (used without object), con·jec·tured, con·jec·tur·ing.

to form conjectures.

Origin of conjecture

1350–1400; (noun) Middle English < Latin conjectūra (< Middle French) inferring, reasoning, equivalent to conject(us) past participle of conjicere to throw together, form a conclusion (con- con- + -jicere, combining form of jacere to throw) + -ūra -ure; (v.) late Middle English conjecturen (< Middle French) < Late Latin conjecturāre, derivative of the noun
Related formscon·jec·tur·a·ble, adjectivecon·jec·tur·a·bly, adverbcon·jec·tur·er, nounmis·con·jec·ture, verb, mis·con·jec·tured, mis·con·jec·tur·ing; nounnon·con·jec·tur·a·ble, adjectivenon·con·jec·tur·a·bly, adverbpre·con·jec·ture, verb (used with object), pre·con·jec·tured, pre·con·jec·tur·ing.un·con·jec·tur·a·ble, adjectiveun·con·jec·tured, adjective

Synonyms for conjecture Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for conjecturing

Historical Examples of conjecturing

British Dictionary definitions for conjecturing



the formation of conclusions from incomplete evidence; guess
the inference or conclusion so formed
obsolete interpretation of occult signs


to infer or arrive at (an opinion, conclusion, etc) from incomplete evidence
Derived Formsconjecturable, adjectiveconjecturably, adverbconjecturer, noun

Word Origin for conjecture

C14: from Latin conjectūra an assembling of facts, from conjicere to throw together, from jacere to throw
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for conjecturing



late 14c., "interpretation of signs and omens," from Old French conjecture "surmise, guess," or directly from Latin coniectura "conclusion, interpretation, guess, inference," literally "a casting together (of facts, etc.)," from coniectus, past participle of conicere "to throw together," from com- "together" (see com-) + iacere "to throw" (see jet (v.)). Sense of "forming of opinion without proof" is 1530s.



early 15c., from conjecture (n.). In Middle English also with a parallel conjecte (n.), conjecten (v.). Related: Conjectured; conjecturing.

Online Etymology Dictionary, © 2010 Douglas Harper