Learner's definition of ESSENCE
the basic nature of a thing
the quality or qualities that make a thing what it is
The essence of love is unselfishness.
The book's illustrations capture the essence of the story.
Competition is the (very) essence of capitalism.
a substance that contains in very strong form the special qualities (such as the taste and smell) of the thing from which it is taken
at the most basic level
He was in essence [=basically, essentially, fundamentally] an honest person.
In essence, I believe that a real solution is not possible.
of the essence
of the greatest importance