the basic, real, and invariable nature of a thing or its significant individual feature or features

Freedom is the very essence of our democracy.

a substance obtained from a plant, drug, or the like, by distillation, infusion, etc., and containing its characteristic properties in concentrated form.

an alcoholic solution of an essential oil; spirit.

a perfume; scent.

Philosophy . the inward nature, true substance, or constitution of anything, as opposed to what is accidental, phenomenal, illusory, etc.

something that exists, esp. a spiritual or immaterial entity. ?

in essence, essentially; at bottom

often despite appearances

For all his bluster, he is in essence a shy person.

of the essence

absolutely essential; critical; crucial

In chess, cool nerves are of the essence.

noun

aspect , attribute , backbone , base , basis , be-all and end-all * , being , bottom , bottom line * , burden , caliber , character , chief constituent , constitution , core , crux , element , entity , essentia , essentiality , fiber , form , fundamentals , germ , grain , kernel , life , lifeblood , main idea , marrow , meaning , meat * , name of game , nature , nitty-gritty * , nub , nucleus , pith , point , principle , property , quality , quiddity , quintessence , reality , root , soul , spirit , structure , stuff , substance , timber , vein , virtuality , balm , cologne , drug , effusion , elixir , extract , fragrance , juice , liquor , perfume , potion , scent , spirits , tincture , texture , gist , meat , alpha and omega , anlage , aroma , attar , aura , bedrock , cachet , component , concoction , constituent , consubstantiality , cornerstone , decoction , desideratum , desiderium , distillate , embodiment , epitome , existence , fundamental , gravamen , heart , hypostasis , indispensable , integrality , linchpin , nitty-gritty , odor , personification , prerequisite , principal , requirement , requisite , significance , sine qua non , substratum , tenor