sphere

¹

[sfeer]

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.

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

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 ).

-sphere

¹

combining form

1. having the shape or form of a sphere

   bathysphere

2. indicating a spherelike enveloping mass

   atmosphere

sphere

²

/ 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

verb

1. to surround or encircle

2. to place aloft or in the heavens

sphere

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

Other Word Forms

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

Word History and Origins

Origin of sphere¹

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

Word History and Origins

Origin of sphere¹

C14: from Late Latin sphēra, from Latin sphaera globe, from Greek sphaira

Example Sentences

Believing that spacetime is a real, physical entity is no more defensible than believing in the old idea of a celestial sphere.

Read more on Science Daily

There’s just too much uninformed, misinformed and self-interested commentary washing about in the investment sphere, too easily accessed by unwary and novice investors.

Read more on Los Angeles Times

A double-digit combination set the social media sphere ablaze among teens in 2025, leaving parents and teachers befuddled -- and now it has officially been crowned Dictionary.com's "Word of the Year": 67.

Read more on Barron's

The Persian Gulf monarchies aren’t traditionally known for moving fast and breaking things, at least in the advanced technology sphere.

Read more on Barron's

The Monroe Doctrine dates back to the U.S. president in 1823 who articulated his opposition to further European colonization of Latin America which he asserted would henceforth be a U.S. sphere of influence.

Read more on MarketWatch

Related Words

• circle 
• field 
• realm 
• scope