kernel (n.) Look up kernel at
"edible substance in a nut or the stone of a fruit," Old English cyrnel "seed, kernel, pip," from Proto-Germanic *kurnilo- (source also of Middle High German kornel "a grain," Middle Dutch cornel "coarse meal"), from the root of corn "seed, grain" (see corn (n.1)) + -el, diminutive suffix. Figurative sense of "core or central part of anything" is from 1550s.