What does "conjecture" mean?

Conjecture: An opinion, or judgment, formed on defective or presumptive evidence; probable inference; surmise; guess; suspicion. He [Herodotus] would thus have corrected his first loose conjecture by a real study of nature. Whewell. Conjectures, fancies, built on nothing firm. Milton.

Additional senses

  1. 2.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.
  2. 3.To make conjectures; to surmise; to guess; to infer; to form an opinion; to imagine.

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