nitty-gritty vs nub

nitty-gritty and nub both are nouns.

Word	Noun	Adjective	Verb	Adverb
nitty-gritty	Yes	No	No	No
nub	Yes	No	No	No

As nouns, nitty-gritty and nub are synonyms defined as:

nitty-gritty and nub: the choicest or most essential or most vital part of some idea or experience

Other synonyms of nitty-gritty include center, centre, core, essence, gist, heart, heart and soul, inwardness, kernel, marrow, meat, pith, substance, sum.

nitty-gritty (noun)	nub (noun)
the choicest or most essential or most vital part of some idea or experience	the choicest or most essential or most vital part of some idea or experience
	a small piece
	a small lump or protuberance