kernel

Meanings

Noun

• The core, center, or essence of an object or system.
• The central (usually edible) part of a nut, especially once the hard shell has been removed.
• A single seed or grain, especially of corn or wheat.
• The stone of certain fruits, such as peaches or plums.
• A small mass around which other matter is concreted; a nucleus; a concretion or hard lump in the flesh.
• The central part of many computer operating systems which manages the system's resources and the communication between hardware and software components.
• The core engine of any complex software system.
• A function used to define an integral transform.
• A set of pairs of a mapping's domain which are mapped to the same value.
• For a given function (especially a linear map between vector spaces), the set of elements in the domain which are mapped to zero; given f : X → Y, the set {x ∈ X : f(x) = 0}.
• For a category with zero morphisms: the equalizer of a given morphism and the zero morphism which is parallel to that given morphism.
• The set of members of a fuzzy set that are fully included (i.e., whose grade of membership is 1).
• The human clitoris.
• The nucleus and electrons of an atom excluding its valence electrons.

Verb

• To enclose within a kernel
• To crenelate

Origin

• From Middle English kernel, kirnel, kurnel, from Old English cyrnel, from Proto-West Germanic *kurnil, diminutive of Proto-Germanic *kurną, equivalent to corn + -le. Cognate with Yiddish קערנדל, Middle Dutch kernel, cornel, Middle High German kornel. Related also to Old Norse kjarni.