Es-sĕn′tiəl1, a.
a. [Fr. essentiel, Pr. & Pg. essencial, Sp. esencial, It. essenziale. See ESSENCE.]
Sense 1. Belonging to the essence, or that which constitutes an object, or class of objects, what they are; really existing.
Is it true, then, that thou art but a name, And no essential thing? J. Webster.
Sense 2. Important in the highest degree; indispensable to the attainment of an object; as, piety is essential to Christian character.
Judgment is more essential to a general than courage. Denham.
Sense 3. Containing the essence or characteristic portion of a substance, as of a plant; highly rectified; pure; hence, unmixed. “Mine own essential horror,” Ford.
Sense 4. (Mus.) Necessary; indispensable; — said of those tones which constitute a chord, in distinction from ornamental or accidental tones.
Sense 5. (Med.) Idiopathic; independent of any other disease.
Essential character (Nat. Hist.), the prominent characteristics which serve to distinguish one genus, species, &c., from another. — Essential disease, one that is not dependent on another. — Essential oil, a volatile, highly inflammable oil, to which plants owe their characteristic odor. It is soluble in alcohol, and is much used in making perfumery.