es·sence /'es-əns/ n
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
2: the predominant purpose of a thing
the essence of the contract
of the essence: of the utmost importance; specif: so material in nature that failure to satisfy its requirements constitutes a breach of contract
time is of the essence>
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.