Belonging to the essence, or that which makes an object, or class of objects, what it is.
- Constituting or being part of the essence of something; inherent.
- Basic or indispensable; necessary: essential ingredients. See Synonyms at indispensable.
- Medicine Of, relating to, or being a dysfunctional condition or a disease whose cause is unknown: essential hypertension.
- Biochemistry Being a substance that is required for normal functioning but cannot be synthesized by the body and therefore must be included in the diet: essential amino acids.
- Something fundamental.
- Something necessary or indispensable.