1 n-uncount The essence of something is its basic and most important characteristic which gives it its individual identity.
usu N of n
The essence of consultation is to listen to, and take account of, the views of those consulted., ...the essence of life... You use in essence to emphasize that you are talking about the most important or central aspect of an idea, situation, or event.
FORMAL
♦
in essence phrase PHR with cl/group (emphasis)
Though off-puttingly complicated in detail, local taxes are in essence simple. If you say that something is of the essence, you mean that it is absolutely necessary in order for a particular action to be successful.
FORMAL
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of the essence phrase V inflects
(=crucial)
Speed was of the essence in a project of this type.