kernel

The core, center, or essence of an object or system.

• the kernel of an argument

The central (usually edible) part of a nut, especially once the hard shell has been removed.

A single seed of grain, especially of corn or wheat.

The stone of certain fruits, such as peaches or plums.US

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 Linux kernel is open-source.

The core engine of any complex software system.

The simplified input to an algorithm that has undergone kernelization.

A function used to define an integral transform.

• The Dirichlet kernel convolved with a function yields its Fourier series approximation.

The set of pairs of elements in the domain of f which are mapped to the same value; the equivalence relation x≡y⟺f(x)=f(y).

• If a function is continuous then its kernel is a closed set.

To enclose within a kernel

To crenellate