The Collaborative International Dictionary of English v.0.48:

Generalization \Gen`er*al*i*za"tion\, n. [Cf. F.
   g['e]n['e]ralisation.]
   [1913 Webster]
   1. The act or process of generalizing; the act of bringing
      individuals or particulars under a genus or class;
      deduction of a general principle from particulars.
      [1913 Webster]

            Generalization is only the apprehension of the one
            in the many.                          --Sir W.
                                                  Hamilton.
      [1913 Webster]

   2. A general inference.
      [1913 Webster]

WordNet (r) 3.0 (2006):

generalization
    n 1: reasoning from detailed facts to general principles [syn:
         generalization, generalisation, induction, inductive
         reasoning]
    2: an idea or conclusion having general application; "he spoke
       in broad generalities" [syn: generalization,
       generalisation, generality]
    3: the process of formulating general concepts by abstracting
       common properties of instances [syn: abstraction,
       generalization, generalisation]
    4: (psychology) transfer of a response learned to one stimulus
       to a similar stimulus [syn: generalization,
       generalisation, stimulus generalization, stimulus
       generalisation]

Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "generalization":
   Baconian method, a fortiori reasoning, a posteriori reasoning,
   a priori reasoning, abstraction, analysis, bromide, catholicity,
   cliche, commonplace, cosmopolitanism, deduction,
   deductive reasoning, ecumenicalism, ecumenicity, epagoge,
   general idea, generality, generalized proposition,
   glittering generality, globalism, globality, hackneyed expression,
   hypothesis and verification, inclusiveness, induction,
   inductive reasoning, inference, internationalism, lieu commun,
   locus communis, particularization, philosophical induction,
   platitude, sweeping statement, syllogism, syllogistic reasoning,
   synthesis, tired cliche, truism, universality, worldwideness