The noun conjecture has 3 senses (first 1 from tagged texts)
1. (1) speculation, conjecture -- (a hypothesis that has been formed by speculating or conjecturing (usually with little hard evidence); "speculations about the outcome of the election"; "he dismissed it as mere conjecture")
2. guess, conjecture, supposition, surmise, surmisal, speculation, hypothesis -- (a message expressing an opinion based on incomplete evidence)
3. conjecture -- (reasoning that involves the formation of conclusions from incomplete evidence)
Overview of verb conjecture
The verb conjecture has 1 sense (first 1 from tagged texts)
1. (1) speculate, theorize, theorise, conjecture, hypothesize, hypothesise, hypothecate, suppose -- (to believe especially on uncertain or tentative grounds; "Scientists supposed that large dinosaurs lived in swamps")