WordRel.com

• unite on a federal basis or band together as a league

  synonym	federalisefederate
  exemplifies	American spelling
  hypernym	unifyunite

• put under the control and authority of a federal government

  synonym	federalise
  derivation	federalizationfederalization
  exemplifies	American spelling
  other	federalizationfederalization
  hypernym	decentralisedecentralizedeconcentrate

• enter into a league for a common purpose

  synonym	federalisefederate
  exemplifies	American spelling
  hypernym	mergeunifyunite