conjecture

noun

1.
a hypothesis that has been formed by speculating or conjecturing (usually with little hard evidence)
daresay plotbeholding reasowing weening speculation
Derived from:
conjectural conjecture
2.
a message expressing an opinion based on incomplete evidence
guess hypothesis speculation supposition surmisal surmise
Derived from:
conjectural
3.
reasoning that involves the formation of conclusions from incomplete evidence
Derived from:
conjectural conjecture