federal (adj.)

1640s, as a theological term (in reference to "covenants" between God and man), from French fédéral, an adjective formed from Latin foedus (genitive foederis) "covenant, league, treaty, alliance" (from PIE *bhoid-es-, suffixed form of root *bheidh- "to trust, confide, persuade").

Secular meaning "pertaining to a covenant or treaty" (1650s) led to political sense of "formed by agreement among independent states" (1707), from use of the word in federal union "union based on a treaty" (popularized during formation of U.S.A. 1776-1787) and like phrases. Also from this period in U.S. history comes the sense "favoring the central government" (1788) and the especial use of the word (as opposed to confederate) to mean a state in which the federal authority is independent of the component parts within its legitimate sphere of action. Used from 1861 in reference to the Northern forces in the American Civil War.

updated on January 31, 2021

Definitions of federal from WordNet
federal (adj.)
national; especially in reference to the government of the United States as distinct from that of its member units;
the federal highway program
federal courts
federal property
federal (adj.)
of or relating to the central government of a federation;
a federal district is one set aside as the seat of the national government
federal (adj.)
characterized by or constituting a form of government in which power is divided between one central and several regional authorities;
federal governments often evolved out of confederations
a federal system like that of the United States
Federal (n.)
a member of the Union Army during the American Civil War;
Synonyms: Federal soldier / Union soldier
Federal (n.)
any federal law-enforcement officer;
Synonyms: Fed / federal official
Federal (adj.)
being of or having to do with the northern United States and those loyal to the Union during the American Civil War;
Synonyms: Union
Etymologies are not definitions. From, not affiliated with etymonline.