Definition of Kernel

• the inner and usually edible part of a seed or grain or nut or fruit stone; "black walnut kernels are difficult to get out of the shell"
• a single whole grain of a cereal; "a kernel of corn"
• the choicest or most essential or most vital part of some idea or experience; "the gist of the prosecutors argument"; "the heart and soul of the Republican Party"; "the nub of the story"