essence
1. Philosophya. the unchanging and unchangeable nature of something which is necessary to its being the thing it is; its necessary properties
b. the properties in virtue of which something is called by its name
c. the nature of something as distinct from, and logically prior to, its existence
2. Theol an immaterial or spiritual entity
3. a. the constituent of a plant, usually an oil, alkaloid, or glycoside, that determines its chemical or pharmacological properties
b. an alcoholic solution of such a substance
4. a substance, usually a liquid, containing the properties of a plant or foodstuff in concentrated form
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005