ETYM French essence, Latin essentia, formed as if from a p. pr. of esse to be. Related to Is, Entity.
Any substance possessing to a high degree the predominant properties of a plant or drug or other natural product from which it is extracted.
In philosophy, all that makes a thing what it is and is indispensable to the thing. Philosophers have often distinguished nominal essences from real essences. A nominal essence is a group of terms used to define a concept: thus, the nominal essence of the concept of a horse could be “anything that neighs and has a mane and four legs”. A real essence is either a group of universals objectively given in nature (this is also called a form) or (as in the work of John Locke) the underlying structure of an object; for example, its atomic structure.