The Collaborative International Dictionary of English v.0.48:

Centralize \Cen"tral*ize\, v. t. [imp. & p. p. Centralized; p.
   pr. & vb. n. Centralizing.] [Cf. F. centraliser.]
   To draw or bring to a center point; to gather into or about a
   center; to bring into one system, or under one control.
   [1913 Webster]

         [To] centralize the power of government. --Bancroft.
   [1913 Webster]

WordNet (r) 3.0 (2006):

centralize
    v 1: make central; "The Russian government centralized the
         distribution of food" [syn: centralize, centralise,
         concentrate] [ant: decentralise, decentralize,
         deconcentrate]