Adjective

(en adjective)

Descending far below the surface; opening or reaching to great depth; deep.

* (rfdate),

A gulf profound

Very deep; very serious

Intellectually deep; entering far into subjects; reaching to the bottom of a matter, or of a branch of learning; thorough; as, a profound investigation or treatise; a profound scholar; profound wisdom.

*

Characterized by intensity; deeply felt; pervading; overmastering; far-reaching; strongly impressed; as, a profound sleep.

* (rfdate),

Profound sciatica

* (rfdate),

Of the profound corruption of this class there can be no doubt.

Bending low, exhibiting or expressing deep humility; lowly; submissive; as, a profound bow.

* (rfdate)

What humble gestures! What profound reverence!

Adjective

(en adjective)

Necessary.

Very important; of high importance.

* {{quote-magazine, date=2013-05-17

, author=George Monbiot, authorlink=George Monbiot , title=Money just makes the rich suffer , volume=188, issue=23, page=19 , magazine=(The Guardian Weekly) citation , passage=In order to grant the rich these pleasures, the social contract is reconfigured. The welfare state is dismantled. Essential public services are cut so that the rich may pay less tax. […]}}

Being in the basic form; showing its essence.

Don’t mind him being grumpy. That’s the essential Fred.

Really existing; existent.

* Webster (1623)

Is it true, that thou art but a name, / And no essential thing?

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.

(medicine) Idiopathic.