zone

1 a : any of five great divisions of the earth's surface with respect to latitude and temperature — compare frigid zone, temperate zone, torrid zone b : a portion of the surface of a sphere included between two parallel planes
2 archaic : girdle, belt
3 a : an encircling anatomical structure b (1) : a subdivision of a biogeographic region that supports a similar fauna and flora throughout its extent (2) : such a zone dominated by a particular life form c : a distinctive belt, layer, or series of layers of earth materials (as rock)
4 : a region or area set off as distinct from surrounding or adjoining parts
5 : one of the sections of an area or territory created for a particular purpose: as a : a zoned section of a city b (1) : any of the eight concentric bands of territory centered on a given postal shipment point designated as a distance bracket for United States parcel post to which mail is charged at a single rate (2) : a distance within which the same fare is charged by a common carrier c : an area on a field of play d : a stretch of roadway or a space in which certain traffic regulations are in force
6 : zone defense
7 : a temporary state of heightened concentration experienced by a performing athlete that enables peak performance <players in the zone>