ESSENTIAL
essential
Noun
- A necessary ingredient.
- A fundamental ingredient.
Adjective
- Necessary.
- Very important; of high importance.
- Being in the basic form; showing its essence.
- Don’t mind him being grumpy. That’s the essential Fred.
- 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.
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