essential

[uh-sen-shuh l] /əˈsɛn ʃəl/
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.
Origin
1300-50; Middle English essencial < Medieval Latin essenciālis for Late Latin essentiālis. See essence, -al1
Related forms
essentially, adverb
essentialness, noun
preessential, noun, adjective
preessentially, adverb
quasi-essential, adjective
quasi-essentially, adverb
subessential, adjective
subessentially, adverb
subessentialness, noun
Synonyms
1. fundamental, basic, inherent, intrinsic, vital. See necessary. 2. Essential, inherent, intrinsic refer to that which is in the natural composition of a thing. Essential suggests that which is in the very essence or constitution of a thing: Oxygen and hydrogen are essential in water. Inherent means inborn or fixed from the beginning as a permanent quality or constituent of a thing: properties inherent in iron. Intrinsic implies belonging to the nature of a thing itself, and comprised within it, without regard to external considerations or accidentally added properties: the intrinsic value of diamonds.
Antonyms
2. incidental, extraneous, extrinsic; accidental.
Examples from the web for essential
  • Data centres are essential to nearly every industry and have become as vital to the functioning of society as power stations are.
  • The ability to maintain organized records is essential.
  • Self control is an essential element of self respect.
  • Experience in an industrial setting is desirable, though not essential.
  • This is probably the most essential tool in the kitchen.
  • The essential ones stay on board.
  • There are many different amino acids in foods but at least 8 of them are essential.
  • Butter is essential because after chilling it firms up the cheese for unmolding.
  • This nest will eventually form rich soil essential to the plant.
  • It is essential for candidates to be conversant with experimental procedures and record keeping.
British Dictionary definitions for essential

essential

/ɪˈsɛnʃəl/
adjective
1.
vitally important; absolutely necessary
2.
basic; fundamental: the essential feature
3.
completely realized; absolute; perfect: essential 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, etc: an 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 cause: essential 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 indispensable: a sharp eye is an essential for a printer
11.
(music) an essential note
Derived Forms
essentiality (ɪˌsɛnʃɪˈælɪtɪ), essentialness, noun
Word Origin and History for essential
adj.

mid-14c., "that is such by its essence," from Late Latin essentialis, from essentia (see essence). Meaning "pertaining to essence" is from late 14c., that of "constituting the essence of something" is from 1540s; that of "necessary" is from 1520s. Essentials "indispensable elements" is from early 16c. Related: Essentially.

essential in Medicine

essential es·sen·tial (ĭ-sěn'shəl)
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.

es·sen'ti·al'i·ty (-shē-āl'ĭ-tē) or es·sen'tial·ness n.