kernel
- 01 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.
Simple“The squirrel cracked the hard shell to reach the sweet kernel inside.”
In context“The recipe calls for toasted pine nut kernels, which provide a rich, buttery texture to the pesto sauce.”
- 02 C1 Advanced
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.
Simple“There was a kernel of truth in his strange story.”
In context“While the initial proposal was flawed, it contained a kernel of brilliance that the design team eventually developed into a successful product.”
- 03 C1 Advanced
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.
Simple“The computer crashed because of a serious error in the kernel.”
In context“Updating the Linux kernel can improve system performance and provide better support for new hardware components.”
UsageUsually used with 'the' in a singular sense.
- 04 C2 Proficiency
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.
Simple“The professor asked the students to find the kernel of the linear transformation.”
In context“In linear algebra, the kernel of a matrix represents the solutions to the homogeneous system of equations.”
Synonymsnull spaceAntonyms
“It is a bit like heating popcorn kernels in a pan.”
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”).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.