Conjecture \Con*jec"ture\, v. t. [imp. & p. p. {Conjectured}; p. pr. & vb. n. {Conjecturing}.] [Cf. F. conjecturer. Cf. {Conject}.] To arrive at by conjecture; to infer on slight evidence; to surmise; to guess; to form, at random, opinions concerning. Human reason can then, at the best, but conjecture what will be. --South.