Defn: Idiopathic; independent of other diseases. Essential character (Biol.), the prominent characteristics which serve to distinguish one genus, species, etc., from another. — Essential disease, Essential fever (Med.), one that is not dependent on another. — Essential oils (Chem.), a class of volatile oils, extracted from plants, fruits, or flowers, having each its characteristic odor, and hot burning taste. They are used in essences, perfumery, etc., and include many varieties of compounds; as lemon oil is a terpene, oil of bitter almonds an aldehyde, oil of wintergreen an ethereal salt, etc.; — called also volatile oils in distinction from the fixed or nonvolatile.
ESSENTIAL
Es*sen"tial, n.
1. Existence; being. [Obs.] Milton.
2. That which is essential; first or constituent principle; as, the essentials or religion.
ESSENTIALITY
Es*sen`ti*al"i*ty, n.
Defn: The quality of being essential; the essential part. Jer.
Taylor.
ESSENTIALLY
Es*sen"tial*ly, adv.
Defn: In an essential manner or degree; in an indispensable degree; really; as, essentially different.
ESSENTIALNESS
Es*sen"tial*ness, n.
Defn: Essentiality. Ld. Digby.