a girdle; a cincture.-one of the five great divisions of the earth, with respect to latitude and temperature.-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.-a band or stripe extending around a body.-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.-a series of planes having mutually parallel intersections.-circuit; circumference.-to girdle; to encircle.