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REFERENCE

planetary

adj. · n.
US //ˈpɫænəˌtɛɹi// UK //plˈænɪtəɹi// plan·e·tary
  1. 1 relating to planets (adj.)
    B2 Upper Intermediate Technical Science

    relating to planets or how they move around a star.

    relating to, or consisting of planets; specifically describing the orbital motion of celestial bodies within a solar system.

    Example

    Scientists are studying the planetary alignment that will happen next month.

    Example

    The probe was designed to withstand the extreme atmospheric pressures found during its descent into the planetary core of Jupiter.

    Usage

    Usually placed before the noun it modifies.
  2. 2 global or worldwide (adj.)
    B2 Upper Intermediate Academic

    relating to the whole Earth and everyone on it.

    relating to the entire planet Earth; often used in environmental or sociological contexts to denote a global scale.

    Example

    Climate change is a planetary problem that requires every country to work together.

    Example

    The report argues that we have already exceeded several planetary boundaries, risking irreversible damage to the Earth's ecosystem.

    Usage

    Commonly used in academic writing regarding the environment or sustainability.
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  1. 3 a type of nebula (n.)
    C2 Proficiency Technical Science

    a short way to say 'planetary nebula', which is a cloud of gas around a dying star.

    A clipped form of 'planetary nebula', referring to an astronomical object consisting of an expanding shell of ionized gas ejected from a red giant star.

    Example

    The astronomer pointed his telescope toward a bright planetary in the constellation.

    Example

    The high-resolution images revealed intricate structures within the planetary, suggesting a complex history of mass loss from the progenitor star.

    Teacher's tip

    This noun use is highly specialized; most learners will only encounter the word as an adjective.
Origin

From planet + -ary.

Word family

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