[{"Bold_text": "noun", "List Items": ["Geometry.a solid geometric figure generated by the revolution of a semicircle about its diameter; a round body whose surface is at all points equidistant from the center. Equation:x2+y2+z2=r2.the surface of such a figure; a spherical .", "a solid geometric figure generated by the revolution of a semicircle about its diameter; a round body whose surface is at all points equidistant from the center. Equation:x2+y2+z2=r2.", "the surface of such a figure; a spherical .", "any rounded body approximately of this form; a globular mass, shell, etc.", "Astronomy.a planet or star; heavenly body. celestial sphere celestial sphere.any of the transparent, concentric, spherical , or layers, in which, according to ancient belief, the planets, stars, and other heavenly bodies were set.", "a planet or star; heavenly body.", "celestial sphere celestial sphere.", "any of the transparent, concentric, spherical , or layers, in which, according to ancient belief, the planets, stars, and other heavenly bodies were set.", "the place or environment within which a person or thing exists; a field of activity or operation:to be out of one's professional sphere.Synonyms: domain , realm , compass , province , area , orbit", "a particular social world, stratum of society, or walk of life:His social sphere is small.Synonyms: rank , class", "a field of something specified:a sphere of knowledge."]}, {"Bold_text": "verb (used with object)", "List Items": ["to enclose in or as if in a sphere.", "to form into a sphere.", "to place among the heavenly spheres."]}, {"Bold_text": null, "List Items": ["a combining form of sphere (planisphere); having a special use in the names of the layers of gases and the like surrounding the earth and other celestial bodies (ionosphere)."]}]