conjecture

nouns

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"
conjecture, speculation
is derived from
conjectural
a message expressing an opinion based on incomplete evidence
conjecture, guess, hypothesis, speculation, supposition, surmisal, surmise
is derived from
conjectural
reasoning that involves the formation of conclusions from incomplete evidence
conjecture
is derived from
conjectural
is a type of (narrower)
thinking that is coherent and logical
abstract thought, logical thinking, reasoning

verbs

to believe especially on uncertain or tentative grounds
"Scientists supposed that large dinosaurs lived in swamps"
conjecture, hypothecate, hypothesise, hypothesize, speculate, suppose, theorise, theorize