zone / zōn/ • n. 1. an area or stretch of land having a particular characteristic, purpose, or use, or subject to particular restrictions: a pedestrian zone. ∎ Geog. a well-defined region extending around the earth between definite limits, esp. between two parallels of latitude. See also frigid zone, temperate zone, torrid zone. ∎ (also time zone) a range of longitudes where a common standard time is used. ∎ Sports in basketball, football, and hockey, a specific area of the court, field, or rink, esp. one to be defended by a particular player, or the mode of defensive play using this system.See zone defense below. ∎ a specific region or area within which uniform rates are charged for transportation, parcel post delivery, or other service. ∎ (in full postal zone) formerly, any of the numbered areas into which a large city or metropolitan area was divided for facilitating mail delivery. ∎ chiefly Bot. & Zool. an encircling band or stripe of distinctive color, texture, or character. 2. Math. an area between two exact or approximate concentric circles. ∎ a part of the surface of a sphere enclosed between two parallel planes, or of a cone or cylinder, etc., between such planes cutting it perpendicularly to the axis. 3. Geol. Paleontology a range between specified limits of depth, height, etc., esp. a section of strata distinguished by characteristic fossils.• v. [tr.] 1. divide into or assign to zones, in particular: ∎ [often as n.] (zoning) divide (a town or stretch of land) into areas subject to particular planning restrictions: an experimental system of zoning. ∎ designate (a specific area) for use or development in such a manner: the land is zoned for housing. 2. archaic encircle as or with a band or stripe.PHRASES: zone defense Sports in basketball, football, and hockey, a system of defensive play in which each player guards an allotted area of the field of play and an opponent only when the opponent is in his area.PHRASAL VERBS: zone out inf. fall asleep or lose concentration or consciousness: I just zoned out for a moment.DERIVATIVES: zon·al / ˈzōnl/ adj.zon·al·ly / ˈzōnl-ē/ adv.ORIGIN: late Middle English: from French, or from Latin zona ‘girdle,’ from Greek zōnē.
1. (biostratigraphic zone) A unit of rock characterized by a clearly defined fossil content. To avoid confusion with other types of zone the term ‘biozone’ (short for ‘biostratigraphic zone’) is preferred by many authorities, although the term ‘biozone’ is also used in a different sense. The term is usually qualified to denote the type of zone. See ACME ZONE; ASSEMBLAGE ZONE; CONCURRENT RANGE ZONE; LINEAGE ZONE; OPPEL ZONE; RANGE ZONE; SUBZONE; TAXON RANGE ZONE; TEILZONE; ZONULE; and INDEX FOSSIL.
2. In crystallography, a set of crystal faces whose intersecting edges are parallel. They are also parallel to, and may be rotated about, a zone axis. See CRYSTAL ZONING.
3. See METAMORPHIC ZONE.