Synonyms:
kernel, substance, core, center, centre, essence, gist, heart, heart_and_soul, inwardness, marrow, meat, nub, pith, sum, nitty-gritty
Meaning: 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"
Synonyms:
nub, stub
Meaning: a small piece; "a nub of coal"; "a stub of a pencil"
Synonyms:
nub, nubble
Meaning: a small lump or protuberance
Usage examples
That, my boy, is the nub, or crux, of the situation.