The Collaborative International Dictionary of English v.0.48:

Categorize \Cat"e*go*rize\, v. t.
   To insert in a category or list; to class; to catalogue.
   [1913 Webster]

WordNet (r) 3.0 (2006):

categorize
    v 1: place into or assign to a category; "Children learn early
         on to categorize" [syn: categorize, categorise]

Moby Thesaurus II by Grady Ward, 1.0:

51 Moby Thesaurus words for "categorize":
   alphabetize, analyze, appraise, arrange, assess, assort, bolt,
   break down, catalog, class, classify, codify, collate, digest,
   divide, evaluate, factor, file, gauge, gradate, grade, group,
   identify, index, list, nail down, order, organize, peg, pigeonhole,
   place, put down, range, rank, rate, riddle, screen, section,
   separate, sieve, sift, size, sort, sort out, subdivide,
   subordinate, tabulate, thrash out, type, weigh, winnow