noun Each of the five regions of the earth's surface into which it was divided by climatic differences, namely the torrid zone (between the tropics), two temperate zones (between the tropics and the polar circles), and two frigid zones (within the polar circles).
noun Any given region or area of the world.
noun A given area distinguished on the basis of a particular characteristic, use, restriction, etc.
There is a no-smoking zone that extends 25 feet outside of each entrance.
noun A restricted category or virtual place.
The discussion was veering off into a danger zone.
noun A band or area of growth encircling anything.
a zone of evergreens on a mountain
noun A band or stripe extending around a body.
noun A series of planes having mutually parallel intersections.
noun The strike zone.
That pitch was low and away, just outside the zone.