federalist

Concise Oxford English Dictionary © 2008 Oxford University Press:
federal/ˈfedərəl/

▶adjective

• 1 having or relating to a system of government in which several states form a unity but remain independent in internal affairs.

• 2 relating to or denoting the central government as distinguished from the separate units constituting a federation.

  ■ (Federal) US historical of the Northern States in the Civil War.

– derivatives
federalism noun,
federalist noun & adjective,
federalization (or federalisation) noun,
federalize (or federalise) verb,
federally adverb.

– origin C17: from L. foedus, foeder- ‘league, covenant’ + -al.