sphere

¹ American  

[sfeer] / sfɪər /

noun

1. Geometry.

   1. 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: x 2 + y 2 + z 2 = r 2 .

   2. the surface of such a figure; a spherical surface.

2. any rounded body approximately of this form; a globular mass, shell, etc.

3. Astronomy.

   1. a planet or star; heavenly body.

   2. celestial sphere.

   3. any of the transparent, concentric, spherical shells, or layers, in which, according to ancient belief, the planets, stars, and other heavenly bodies were set.

4. 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

5. a particular social world, stratum of society, or walk of life.

   His social sphere is small.

   Synonyms:

   rank, class

6. a field of something specified.

   a sphere of knowledge.

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verb (used with object)

sphered, sphering

1. to enclose in or as if in a sphere.

2. to form into a sphere.

3. to place among the heavenly spheres.

-sphere ² American  

1. 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 ).

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-sphere ¹ British  

combining form

1. having the shape or form of a sphere

   bathysphere

2. indicating a spherelike enveloping mass

   atmosphere

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sphere ² British  

/ sfɪə /

noun

1. maths

   1. a three-dimensional closed surface such that every point on the surface is equidistant from a given point, the centre

   2. the solid figure bounded by this surface or the space enclosed by it. Equation: ( x–a )² + ( y–b )² + ( z–c )² = r ², where r is the radius and ( a, b, c ) are the coordinates of the centre; surface area: 4π r ²; volume: 4π r ³/3

2. any object having approximately this shape; globe

3. the night sky considered as a vaulted roof; firmament

4. any heavenly object such as a planet, natural satellite, or star

5. (in the Ptolemaic or Copernican systems of astronomy) one of a series of revolving hollow globes, arranged concentrically, on whose transparent surfaces the sun (or in the Copernican system the earth), the moon, the planets, and fixed stars were thought to be set, revolving around the earth (or in the Copernican system the sun)

6. particular field of activity; environment

   that's out of my sphere

7. a social class or stratum of society

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verb

1. to surround or encircle

2. to place aloft or in the heavens

sphere Scientific  

/ sfîr /

1. A three-dimensional geometric surface having all of its points the same distance from a given point.

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Other Word Forms

• -spheric combining form
• sphereless adjective
• spherelike adjective
• subsphere noun
• unsphering adjective

Etymology

Origin of sphere

1250–1300; < Late Latin sphēra, Latin sphaera globe < Greek sphaîra ball; replacing Middle English spere < Old French spere < Late Latin spēra, variant of sphēra

Example Sentences

They read popular almanacs, and learned and admired the intricacies of orreries—mechanical models of the celestial sphere—that they flocked to view at numerous colleges.

From The Wall Street Journal

“The online sphere is 100% key to these attacks,” said Hans-Jakob Schindler, the former coordinator of the United Nations Security Council’s panel on Islamic State and al Qaeda.

From The Wall Street Journal

“Somehow, another woman in the political sphere whose name starts with ‘M’ has written a book this year with ‘Finding’ and ‘Way’ in the title.

From Los Angeles Times

The Eagles will be back at the Sphere in January.

From Los Angeles Times

When location-sharing data moves into a sphere where it’s considered bad social etiquette to receive a location without sharing one back, I start to worry about the deeper ramifications of this technology.

From Slate

Related Words

• circle
• field
• realm
• scope