a zone in central Panama, crossing the Isthmus of Panama on both sides of the panama canal: governed by the U.S. from 1903 until 1979, when most of the zone was returned to Panama, for its eventual control of the entire zone by 2000; about 10 miles (16 km) wide; excludes the cities of Panama and Colón. 44,650; 553 sq. mi. (1432 sq. km). Abbreviation: CZ (for use with zip code), C. Z.
Also called: Panama Canal Zone a former administrative region of the US, on the Isthmus of Panama around the Panama Canal: bordered on each side by the Republic of Panama, into which it was incorporated in 1979