essence vs nitty-gritty

essence and nitty-gritty both are nouns.

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

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

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

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

essence (noun)	nitty-gritty (noun)
a toiletry that emits and diffuses a fragrant odor	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
the central meaning or theme of a speech or literary work
any substance possessing to a high degree the predominant properties of a plant or drug or other natural product from which it is extracted