The Collaborative International Dictionary of English v.0.48:

Infer \In*fer"\, v. t. [imp. & p. p. Inferred; p. pr. & vb. n.
   Inferring.] [L. inferre to bring into, bring forward,
   occasion, infer; pref. in- in + ferre to carry, bring: cf. F.
   inf['e]rer. See 1 st Bear.]
   [1913 Webster]
   1. To bring on; to induce; to occasion. [Obs.] --Harvey.
      [1913 Webster]

   2. To offer, as violence. [Obs.] --Spenser.
      [1913 Webster]

   3. To bring forward, or employ as an argument; to adduce; to
      allege; to offer. [Obs.]
      [1913 Webster]

            Full well hath Clifford played the orator,
            Inferring arguments of mighty force.  --Shak.
      [1913 Webster]

   4. To derive by deduction or by induction; to conclude or
      surmise from facts or premises; to accept or derive, as a
      consequence, conclusion, or probability; as, I inferred
      his determination from his silence.
      [1913 Webster]

            To infer is nothing but by virtue of one proposition
            laid down as true, to draw in another as true.
                                                  --Locke.
      [1913 Webster]

            Such opportunities always infer obligations.
                                                  --Atterbury.
      [1913 Webster]

   5. To show; to manifest; to prove. [Obs.]
      [1913 Webster]

            The first part is not the proof of the second, but
            rather contrariwise, the second inferreth well the
            first.                                --Sir T. More.
      [1913 Webster]

            This doth infer the zeal I had to see him. --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

infer
    v 1: reason by deduction; establish by deduction [syn: deduce,
         infer, deduct, derive]
    2: draw from specific cases for more general cases [syn:
       generalize, generalise, extrapolate, infer]
    3: conclude by reasoning; in logic [syn: deduce, infer]
    4: guess correctly; solve by guessing; "He guessed the right
       number of beans in the jar and won the prize" [syn: guess,
       infer]
    5: believe to be the case; "I understand you have no previous
       experience?" [syn: understand, infer]

Moby Thesaurus II by Grady Ward, 1.0:

84 Moby Thesaurus words for "infer":
   allegorize, allude to, analyze, apply reason, assume, be afraid,
   believe, bring to mind, collect, conceive, conclude, connote,
   consider, daresay, deduce, deduct, deem, derive, divine, dope,
   draw, draw a conclusion, draw an inference, dream, entail, expect,
   extract, fancy, feel, fetch, find, gather, generalize, glean,
   grant, guess, hint, hypothesize, imagine, implicate, imply, import,
   induce, insinuate, intellectualize, intimate, involve, let, let be,
   logicalize, logicize, mean, mean to say, opine, philosophize,
   point indirectly to, prefigure, presume, presuppose, presurmise,
   provide a rationale, provisionally accept, rationalize, reason,
   reason that, reckon, repute, say, suggest, suppose, surmise,
   suspect, syllogize, synthesize, take, take as proved, take for,
   take for granted, take it, take to be, theorize, think, understand,
   use reason