"nub" in the noun sense
1. nub, nubble
a small lump or protuberance
2. nub, stub
a small piece
"a nub of coal"
"a stub of a pencil"
3. kernel, substance, core, center, centre, essence, gist, heart, heart and soul, inwardness, marrow, meat, nub, pith, sum, nitty-gritty
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"
Source: WordNet® (An amazing lexical database of English)
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