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.-a single seed or grain; as, a kernel of corn.-a small mass around which other matter is concreted; a nucleus; a concretion or hard lump in the flesh.-the central, substantial or essential part of anything; the gist; the core; as, the kernel of an argument.-to harden or ripen into kernels; to produce kernels.