Essence

Definition of Essence

That which is indispensable. The gist or substance of any act; the vital constituent of a thing; that without which a thing cannot be itself. Norman v. Department of Labor and Industries, 10 Wash.2d 180, 116 P.2d 360, 362.

That's the definition of Essence in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.