Meaning

noun the inner and usually edible part of a seed or grain or nut or fruit stone

noun a single whole grain of a cereal

noun the choicest or most essential or most vital part of some idea or experience

originFrom Middle English kernel, kirnel, kürnel, from Old English cyrnel, from Proto-West Germanic *kurnil, diminutive of Proto-Germanic *kurną (“seed, grain, corn”), equivalent to corn + -le. Cognate with Yiddish קערנדל (kerndl), Middle Dutch kernel, cornel, Middle High German kornel. Related also to Old Norse kjarni (“kernel”).

Etymology from Wiktionary, CC BY-SA 3.0