1.A girdle; a cincture. (Poetic) "An embroidered zone surrounds her waist." "Loose were her tresses seen, her zone unbound."
2.(Geog.) One of the five great divisions of the earth, with respect to latitude and temperature. Note: The zones are five: the torrid zone, extending from tropic to tropic 46° 56', or 23° 28' on each side of the equator; two temperate or variable zones, situated between the tropics and the polar circles; and two frigid zones, situated between the polar circles and the poles. "Commerce... defies every wind, outrides every tempest, and invades."
3.(Math.) The portion of the surface of a sphere included between two parallel planes; the portion of a surface of revolution included between two planes perpendicular to the axis.
5.(Crystallog.) A series of planes having mutually parallel intersections.
6.Circuit; circumference. (R.)
7.(Biogeography) An area or part of a region characterized by uniform or similar animal and plant life; a life zone; as, Littoral zone, Austral zone, etc. Note: The zones, or life zones, commonly recognized for North America are Arctic, Hudsonian, Canadian, Transition, Upper Austral, Lower Austral, and Tropical.
8.(Cryst.) A series of faces whose intersection lines with each other are parallel.
10.Any area to or within which a shipment or transportation cost is constant; specifically, In the United States parcel-post system, any of the areas about any point of shipment for which but one rate of postage is charged for a parcel post shipment from that point. The rate increases from within outwards. The first zone includes the unit of area "(a quadrangle 30 minutes square)" in which the place of shipment is situated and the 8 contiguous units; the outer limits of the second to the seventh zones, respectively, are approximately 150, 300, 600, 1000, 1400, and 1800 miles from the point of shipment; the eighth zone includes all units of area outside the seventh zone.
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