the choicest or most essential or most vital part of some idea or experience; "the gist of the prosecutor's argument"; "the heart and soul of the Republican Party"; "the nub of the story"
a single whole grain of a cereal; "a kernel of corn"
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"
an emotion of great sadness associated with loss or bereavement; "he tried to express his sorrow at her loss"
sadness associated with some wrong done or some disappointment; "he drank to drown his sorrows"; "he wrote a note expressing his regret"; "to his rue, the error cost him the game"