1. (a.) Pertaining to a league or treaty; derived from an agreement or covenant between parties, especially between nations; constituted by a compact between parties, usually governments or their representatives.
2. (a.) Composed of states or districts which retain only a subordinate and limited sovereignty, as the Union of the United States, or the Sonderbund of Switzerland.
3. (a.) Consisting or pertaining to such a government; as, the Federal Constitution; a Federal officer.
4. (a.) Friendly or devoted to such a government; as, the Federal party. See Federalist.