n. The act of forming an opinion without definite proof; a supposition made to account for an ascertained state of things, but as yet unverified; an opinion formed on insufficient presumptive evidence; a surmise; a guess.n. Suspicious surmise; derogatory supposition or presumption.n. Synonyms Supposition, hypothesis, theory.To form (an opinion or notion) upon probabilities or upon slight evidence; guess: generally governing a clause.Synonyms Imagine, Conjecture, Surmise, Guess, Presume, fancy, divine. Imagine literally expresses pure speculation, and figuratively expresses an idea founded upon the slightest evidence: as, I imagine that you will find yourself mistaken. Conjecture is something like a random throw of the mind; it turns from one possibility to another, and perhaps selects one, almost arbitrarily. Surmise has often the same sense as conjecture; it sometimes implies a suspicion, favorable or otherwise: as, I surmise that his motives were not good. Guess suggests a riddle, the solution of which is felt after by the mind—a question, as to which we offer an opinion, but not with confidence, because the material for a judgment is confessedly insufficient. To presume is to base a tentative or provisional opinion on such knowledge as one has, to be held until it is modified or overthrown by further information.To form conjectures; surmise; guess.