essence

noun | \ ˈes-ᵊns \ | es·sence
  1. : the real or ultimate nature of a thing : the properties that make a thing what it is his award is legitimate only so long as it draws its essence from the collective bargaining agreement —United Steel Workers v. Enterprise Wheel and Car Corp., 363 U.S. 593 (1960) — see also essence test

  1. : the predominant purpose of a thing the essence of the contract