The Collaborative International Dictionary of English v.0.48:

Assortment \As*sort"ment\ (-ment), n. [Cf. F. assortiment.]
   1. Act of assorting, or distributing into sorts, kinds, or
      classes.
      [1913 Webster]

   2. A collection or quantity of things distributed into kinds
      or sorts; a number of things assorted.
      [1913 Webster]

   3. A collection containing a variety of sorts or kinds
      adapted to various wants, demands, or purposes; as, an
      assortment of goods.
      [1913 Webster]

WordNet (r) 3.0 (2006):

assortment
    n 1: a collection containing a variety of sorts of things; "a
         great assortment of cars was on display"; "he had a variety
         of disorders"; "a veritable smorgasbord of religions" [syn:
         assortment, mixture, mixed bag, miscellany,
         miscellanea, variety, salmagundi, smorgasbord,
         potpourri, motley]
    2: the act of distributing things into classes or categories of
       the same type [syn: categorization, categorisation,
       classification, compartmentalization,
       compartmentalisation, assortment]