Federal means belonging to the central government of a union of states. Federal law, a federal agency, federal elections.
The whole point of a federal system is that the centre and the states each hold powers the other cannot simply take, and disputes between them go to a court. About forty per cent of the world's people live under one. The Latin foedus means a treaty.
1adjectivefederalBelonging to the central government of a union of states.
“Crimes that cross state borders are often investigated by federal agents.”
federal is a form of government.
French
fédéral
English, today
federal
Borrowed from French fédéral.
Etymology from Wiktionary, CC BY-SA