solemn

As an adjective solemn

is deeply serious and somber.

As a noun solitude is

aloneness; state of being alone or solitary, by oneself.

As an adjective solemn

is deeply serious and somber.

As an adverb really is

(lb) actually; in fact; in reality.

As an interjection really is

indicating surprise at, or requesting confirmation of, some new information; to express skepticism.

As adjectives the difference between solemn and demure

is that solemn is deeply serious and somber while demure is quiet, modest, reserved, sober, or serious.

As a verb demure is

(obsolete) to look demurely.

As adjectives the difference between polite and solemn

is that polite is well-mannered, civilized while solemn is deeply serious and somber.

As a verb polite

is (obsolete|transitive) to polish; to refine; to render polite.

As adjectives the difference between solemn and awestruck

is that solemn is deeply serious and somber while awestruck is filled or overcome with awe or wonder.

As adjectives the difference between solemn and ceremonial

is that solemn is deeply serious and somber while ceremonial is of, relating to, or used in a ceremony; ritual or formal.

As a noun ceremonial is

a ceremony, or series of ceremonies, prescribed by ritual.

As adjectives the difference between solemn and measured

is that solemn is deeply serious and somber while measured is that has been determined by measurement.

As a verb measured is

(measure).

As adjectives the difference between solemn and significant

is that solemn is deeply serious and somber while significant is signifying something; carrying meaning.

As a noun significant is

that which has significance; a sign; a token; a symbol.

As an adjective solemn

is deeply serious and somber.

As a noun rigor is

.

As adjectives the difference between solemn and restrictive

is that solemn is deeply serious and somber while restrictive is confining, limiting, containing with in defined bounds.