FEDERATION

[noun] - a group of regions or states united with a central government which has control over some things such as defence, but with each region having its own local government and laws, or the act of forming such a groupThe United States is a federation of 50 individual states. [C]The Federation of the six original Australian states took place in 1901. [C]He's against European federation (= the joining together of a group of regions). [U]