The Collaborative International Dictionary of English v.0.48:

Federal \Fed"er*al\, a. [L. foedus league, treaty, compact; akin
   to fides faith: cf. F. f['e]d['e]ral. see Faith.]
   1. 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.
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            The Romans compelled them, contrary to all federal
            right, . . . to part with Sardinia.   --Grew.
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   2. Specifically:
      (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.
      (b) Consisting or pertaining to such a government; as, the
          Federal Constitution; a Federal officer.
      (c) Friendly or devoted to such a government; as, the
          Federal party. see Federalist.
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   Federal Congress. See under Congress.
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