Conjecture (n.) An opinion, or judgment, formed on defective or presumptive evidence; probable inference; surmise; guess; suspicion.

Conjecture (v. t.) To arrive at by conjecture; to infer on slight evidence; to surmise; to guess; to form, at random, opinions concerning.

Conjecture (v. i.) To make conjectures; to surmise; to guess; to infer; to form an opinion; to imagine.