1historical In Argentina in the early and mid 19th century: (collectively) the advocates or supporters of a devolved or federal (rather than centralized) system of government. Compare Unitario .
2In Mexico: (originally) the national army; (now usually) a federal law enforcement agency; the members of such an agency collectively. Also in extended use, often in Spanish-speaking contexts: (the members of) a U.S. federal agency, especially the FBI.
3In singular form federale. A Mexican federal law enforcement agent. Also in extended use: a U.S. federal agent.
Early 19th century; earliest use found in Trumpet & Universalist Magazine. From American Spanish federales, plural of federal, specific uses as noun of federal.