‖n.; pl. Zonae [ L., a girdle. See Zone. ] A zone or band; a layer. [ 1913 Webster ]

Zona pellucida. [ NL. ] (Biol.) (a) The outer transparent layer, or envelope, of the ovum. It is a more or less elastic membrane with radiating striae, and corresponds to the cell wall of an ordinary cell. See Ovum, and Illust. of Microscope. (b) The zona radiata. --
Zona radiata [ NL. ] (Biol.), a radiately striated membrane situated next the yolk of an ovum, or separated from it by a very delicate membrane only. [ 1913 Webster ]

a. [ L. zonalis. ] Of or pertaining to a zone; having the form of a zone or zones. [ 1913 Webster ]

Zonal equation (Crystallog.), the mathematical relation which belongs to all the planes of a zone, and expresses their common position with reference to the axes. --
Zonal structure (Crystallog.), a structure characterized by the arrangements of color, inclusions, etc., of a crystal in parallel or concentric layers, which usually follow the outline of the crystal, and mark the changes that have taken place during its growth. --
Zonal symmetry. (Biol.) See the Note under Symmetry. [ 1913 Webster ]

n. [ Mod. Gr. &unr_; a girdle, fr. Gr. &unr_;, dim. of &unr_; a girdle. See Zone. ] A belt or girdle which the Christians and Jews of the Levant were obliged to wear to distinguish them from Mohammedans. [ Written also zonnar. ] [ 1913 Webster ]

‖n. pl. [ NL. ] (Zool.) A division of Mammalia in which the placenta is zonelike. [ 1913 Webster ]

a. (Bot.) Divided by parallel planes; as, zonate tetraspores, found in certain red algae. [ 1913 Webster ]

v. t. To girdle; to encircle. [ R. ] Keats. [ 1913 Webster ]

n. [ F. zone, L. zona, Gr. zw`nh; akin to zwnny`nai to gird, Lith. jůsta a girdle, jůsti to gird, Zend yāh. ] 1. A girdle; a cincture. [ Poetic ] [ 1913 Webster ]

An embroidered zone surrounds her waist. Dryden. [ 1913 Webster ]

Loose were her tresses seen, her zone unbound. Collins. [ 1913 Webster ]

2. (Geog.) One of the five great divisions of the earth, with respect to latitude and temperature. [ 1913 Webster ]

☞ 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. [ 1913 Webster ]

Commerce . . . defies every wind, outrides every tempest, and invades. Bancroft. [ 1913 Webster ]

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. Davies & Peck (Math. Dict.) [ 1913 Webster ]

4. (Nat. Hist.) (a) A band or stripe extending around a body. (b) A band or area of growth encircling anything; as, a zone of evergreens on a mountain; the zone of animal or vegetable life in the ocean around an island or a continent; the Alpine zone, that part of mountains which is above the limit of tree growth. [ 1913 Webster ]

5. (Crystallog.) A series of planes having mutually parallel intersections. [ 1913 Webster ]

6. Circuit; circumference. [ R. ] Milton. [ 1913 Webster ]

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. The zones, or life zones, commonly recognized for North America are Arctic, Hudsonian, Canadian, Transition, Upper Austral, Lower Austral, and Tropical. [ Webster 1913 Suppl. ]

8. (Cryst.) A series of faces whose intersection lines with each other are parallel. [ Webster 1913 Suppl. ]

9. (Railroad Econ.) (a) The aggregate of stations, in whatsoever direction or on whatsoever line of railroad, situated between certain maximum and minimum limits from a point at which a shipment of traffic originates. (b) Any circular or ring-shaped area within which the street-car companies make no differences of fare. [ Webster 1913 Suppl. ]

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. [ Webster 1913 Suppl. +PJC ]

Abyssal zone. (Phys. Geog.) See under Abyssal. --
Zone axis (Crystallog.), a straight line passing through the center of a crystal, to which all the planes of a given zone are parallel. [ 1913 Webster ]

a. 1. Wearing a zone, or girdle. Pope. [ 1913 Webster ]

2. Having zones, or concentric bands; striped. [ 1913 Webster ]

3. (Bot.) Zonate. [ 1913 Webster ]

a. Not having a zone; ungirded. [ 1913 Webster ]

The reeling goddess with the zoneless waist. Cowper. [ 1913 Webster ]

In careless folds, loose fell her zoneless vest. Mason. [ 1913 Webster ]

n. See Zonar. [ 1913 Webster ]