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sphere

US //ˈsfɪɹ// UK //sfˈiə// sphere
  1. 1 a round object (n.)
    B2 Upper Intermediate Math

    a solid object that is perfectly round, like a ball.

    a three-dimensional object or surface where all points are equidistant from a central point.

    Example

    The artist placed a large marble sphere in the center of the garden.

    Example

    The physicist calculated the volume of the sphere to determine how much liquid the container could hold under pressure.

  2. 2 area of activity (n.)
    C1 Advanced Academic

    a particular area of interest, work, or influence.

    a metaphorical domain or field of activity, interest, or social standing.

    Example

    The two countries agreed to respect each other's sphere of influence.

    Example

    In the political sphere, the senator was known for her ability to build consensus among opposing factions.

    Usage

    Often used in the phrase 'sphere of influence' or 'public/private sphere'.

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  1. 3 the heavens (n.)
    C2 Proficiency Archaic Literary Astronomy

    the sky or space, imagined as a giant globe surrounding the Earth.

    the celestial shell or heavens, historically conceived as a series of concentric globes carrying the planets.

    Example

    Ancient astronomers believed the stars were fixed to a crystal sphere.

    Example

    The poet wrote of the music of the spheres, imagining the harmonious sounds created by the movement of the planets.

    Teacher's tip

    This sense is largely restricted to historical or literary contexts discussing pre-modern science.

  2. 4 to make round (v.)
    C2 Proficiency Literary

    to make something into the shape of a ball.

    to form into a round shape or to place within a spherical environment.

    Example

    The water droplets began to sphere as they fell through the air.

    Example

    The sculptor worked the clay until he managed to sphere the mass into a perfectly balanced form.

    Usage

    This verb use is rare in modern English; 'shape into a sphere' is more common.

Origin

From Middle English spere, from Old French sphere, from Late Latin sphēra, earlier Latin sphaera (“ball, globe, celestial sphere”), from Ancient Greek σφαῖρα (sphaîra, “ball, globe”), of unknown origin. Not related to superficially similar Persian سپهر (sepehr, “sky”) .

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