conjecture: [14] A conjecture is, etymologically speaking, simply something ‘thrown together’. The word comes, perhaps via Old French, from Latin conjectūra ‘conclusion, interpretation’, a noun derived from the past participle of conicere ‘throw together’. This was a compound verb formed from the prefix com- ‘together’ and jacere ‘throw’ (source of English jet, jettison, and jetty). The notion behind the word’s semantic development is that facts are ‘thrown together’ in the mind and (provisional) conclusions drawn. => jet, jettison, jetty
conjecture (n.)
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.
conjecture (v.)
early 15c., from conjecture (n.). In Middle English also with a parallel conjecte (n.), conjecten (v.). Related: Conjectured; conjecturing.
