Kernel n. : The essential part of a seed; all that is within the seed walls; the edible substance contained in the shell of a nut; hence, anything included in a shell, husk, or integument; as, the kernel of a nut. See Illust. of Endocarp.

Kernel n. : A single seed or grain; as, a kernel of corn.

Kernel n. : A small mass around which other matter is concreted; a nucleus; a concretion or hard lump in the flesh.

Kernel n. : The central, substantial or essential part of anything; the gist; the core; as, the kernel of an argument.

Kernel v. i. : To harden or ripen into kernels; to produce kernels.

Example:
What is the difference between Kernel and shell in operating system?

Taxonomy
kernel, operating system, microkernel, processes, design, monolithic kernels, memory, protection, application, mechanism, implementation, processor, capabilities, acm, address space, computer, system calls, execution.

Defination from the web:
kernel concept. ... The kernel, from this viewpoint, is simply the name given to the lowest level of abstraction that is implemented in software. In order to avoid having a kernel, one would have to design all the software on the system not to use ...