What is the meaning of essence?

noun

• The choicest or most essential or most vital part of some idea or experience.
  • usage: "the gist of the prosecutor's argument"; "the heart and soul of the Republican Party"; "the nub of the story"
  • synonyms: kernel, substance, core, center, centre, gist, heart, heart and soul, inwardness, marrow, meat, nub, pith, sum, nitty-gritty
• Any substance possessing to a high degree the predominant properties of a plant or drug or other natural product from which it is extracted.
• The central meaning or theme of a speech or literary work.
  • synonyms: effect, burden, core, gist
• A toiletry that emits and diffuses a fragrant odor.
  • synonyms: perfume