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kernel

n.
US //ˈkɝnəɫ// UK //kˈɜːnəl// ker·nel
  1. 1 seed or nut (n.)
    B2 Upper Intermediate

    the inner part of a nut or a single grain of corn.

    the inner, usually edible part of a nut or fruit stone, or a single whole grain of a cereal plant.

    Example

    The squirrel cracked the hard shell to reach the sweet kernel inside.

    Example

    The recipe calls for toasted pine nut kernels, which provide a rich, buttery texture to the pesto sauce.
  2. 2 core idea (n.)
    C1 Advanced Formal

    the most important part of an idea or a story.

    the central or essential part of a concept, plan, or story around which other details are built.

    Example

    There was a kernel of truth in his strange story.

    Example

    While the initial proposal was flawed, it contained a kernel of brilliance that the design team eventually developed into a successful product.
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  1. 3 computing (n.)
    C1 Advanced Technical Computing

    the most important part of a computer's software that controls the hardware.

    the fundamental part of an operating system that manages system resources and communication between hardware and software.

    Example

    The computer crashed because of a serious error in the kernel.

    Example

    Updating the Linux kernel can improve system performance and provide better support for new hardware components.

    Usage

    Usually used with 'the' in a singular sense.
  2. 4 mathematics (n.)
    C2 Proficiency Technical Math

    a special set of numbers or values in a mathematical function.

    the set of elements in the domain of a function that are mapped to the identity element or zero.

    Example

    The professor asked the students to find the kernel of the linear transformation.

    Example

    In linear algebra, the kernel of a matrix represents the solutions to the homogeneous system of equations.
    • null space
Origin

From Middle English kernel, kirnel, kürnel, from Old English cyrnel, from Proto-West Germanic kurnil, diminutive of Proto-Germanic kurną (“seed, grain, corn”), equivalent to corn + -le. Cognate with Yiddish קערנדל (kerndl), Middle Dutch kernel, cornel, Middle High German kornel. Related also to Old Norse kjarni (“kernel”).

Idioms1 entry

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