[syn: speculate, theorize, theorise, conjecture, hypothesize, hypothesise, hypothecate, suppose]
The Collaborative International Dictionary of English v.0.48:
Conjecture \Con*jec"ture\ (; 135?), n. [L. conjectura, fr.
   conjicere, conjectum, to throw together, infer, conjecture;
   con- + jacere to throw: cf. F. conjecturer. See Jet a
   shooting forth.]
   An opinion, or judgment, formed on defective or presumptive
   evidence; probable inference; surmise; guess; suspicion.
   [1913 Webster]
         He [Herodotus] would thus have corrected his first
         loose conjecture by a real study of nature. --Whewell.
   [1913 Webster]
         Conjectures, fancies, built on nothing firm. --Milton.
   [1913 Webster]
The Collaborative International Dictionary of English v.0.48:
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.
   [1913 Webster]
         Human reason can then, at the best, but conjecture what
         will be.                                 --South.
   [1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Conjecture \Con*jec"ture\, v. i.
   To make conjectures; to surmise; to guess; to infer; to form
   an opinion; to imagine.
   [1913 Webster]
WordNet (r) 3.0 (2006):
conjecture
    n 1: a hypothesis that has been formed by speculating or
         conjecturing (usually with little hard evidence);
         "speculations about the outcome of the election"; "he
         dismissed it as mere conjecture" [syn: speculation,
         conjecture]
    2: a message expressing an opinion based on incomplete evidence
       [syn: guess, conjecture, supposition, surmise,
       surmisal, speculation, hypothesis]
    3: reasoning that involves the formation of conclusions from
       incomplete evidence
    v 1: to believe especially on uncertain or tentative grounds;
         "Scientists supposed that large dinosaurs lived in swamps"
         [syn: speculate, theorize, theorise, conjecture,
         hypothesize, hypothesise, hypothecate, suppose]
Moby Thesaurus II by Grady Ward, 1.0:
56 Moby Thesaurus words for "conjecture":
   assume, assumption, axiom, believe, blind guess, bold conjecture,
   conceive, conclude, deem, estimate, expect, fancy, feel, gather,
   give a guess, glean, guess, guesswork, hazard a conjecture, hunch,
   hypothesis, imagine, infer, inference, judge, perhaps, postulate,
   postulation, postulatum, premise, presume, presumption,
   presupposal, presupposition, pretend, proposition, risk assuming,
   rough guess, set of postulates, shot, speculation, stab, supposal,
   suppose, supposing, supposition, surmise, suspect,
   take for granted, tentatively suggest, thesis, think,
   unverified supposition, venture a guess, wild guess,
   working hypothesis