Kernel

Kernel
1. 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.
2. A single seed or grain; as, a kernel of corn.
3. A small mass around which other matter is concreted; a nucleus; a concretion or hard lump in the flesh.
4. The central, substantial or essential part of anything; the gist; the core; as, the kernel of an argument.
Origin: oe. Kernel, kirnel, curnel, as.cyrnel, fr. Corn grain. See corn, and cf. Kern to harden.