Source : Webster's Revised Unabridged Dictionary (1913)

Federalize \Fed"er*al*ize\, v. t. [imp. & p. p. {Federalized};
   p. pr. & vb. n. {Federalizing}.] [Cf. F. f['e]d['e]raliser.]
   To unite in compact, as different States; to confederate for
   political purposes; to unite by or under the Federal
   Constitution. --Barlow.

Source : WordNet®

federalize
     v 1: unite on a federal basis or band together as a league; "The
          country was federated after the civil war" [syn: {federate},
           {federalise}]
     2: put under the control and authority of a federal government
        [syn: {federalise}]
     3: enter into a league for a common purpose; "The republics
        federated to become the Soviet Union" [syn: {federate}, {federalise}]