essentialness

adjective

1. absolutely necessary; indispensable: Discipline is essential in an army.
2. pertaining to or constituting the essence of a thing.
3. noting or containing an essence of a plant, drug, etc.
4. being such by its very nature or in the highest sense; natural; spontaneous: essential happiness.
5. Mathematics.
   1. (of a singularity of a function of a complex variable) noting that the Laurent series at the point has an infinite number of terms with negative powers.
   2. (of a discontinuity) noting that the function is discontinuous and has no limit at the point.Compare removable(def 2).

noun

6. a basic, indispensable, or necessary element; chief point: Concentrate on essentials rather than details.

adjective

1. vitally important; absolutely necessary
2. basic; fundamentalthe essential feature
3. completely realized; absolute; perfectessential beauty
4. biochem (of an amino acid or a fatty acid) necessary for the normal growth of an organism but not synthesized by the organism and therefore required in the diet
5. derived from or relating to an extract of a plant, drug, etcan essential oil
6. logic (of a property) guaranteed by the identity of the subject; necessary. Thus, if having the atomic number 79 is an essential property of gold, nothing can be gold unless it has that atomic number
7. music denoting or relating to a note that belongs to the fundamental harmony of a chord or piece
8. pathol (of a disease) having no obvious external causeessential hypertension
9. geology (of a mineral constituent of a rock) necessary for defining the classification of a rock. Its absence alters the rock’s name and classification

noun

10. something fundamental or indispensablea sharp eye is an essential for a printer
11. music an essential note

adj.

1. Constituting or being part of the essence of something; inherent.
2. Basic or indispensable; necessary.
3. Of, relating to, or being a dysfunctional condition or a disease whose cause is unknown.
4. Of, relating to, or being a substance that is required for normal functioning but cannot be synthesized by the body and therefore must be included in the diet.

n.

1. Something fundamental.
2. Something necessary or indispensable.