What is the meaning of Essential?
Very important; of high importance.
Necessary for survival but not synthesized by the organism, thus needing to be ingested.
Being in the basic form; showing its essence.
Really existing; existent.
Such that each complementary region is irreducible, the boundary of each complementary region is incompressible by disks and monogons in the complementary region, and no leaf is a sphere or a torus bounding a solid torus in the manifold.
Having the nature of essence; not physical.
A fundamental ingredient.
Source: wiktionary.orgSearch words containing