somberly

As an adjective quiet

is with little or no sound; free from of disturbing noise.

As a verb quiet

is to become quiet, silent, still, tranquil, calm.

As a noun quiet

is the absence of sound; quietness.

As an adverb somberly is

in a somber manner.

As an adjective melancholy

is affected with great sadness or depression.

As a noun melancholy

is (historical) black bile, formerly thought to be one of the four "cardinal humours" of animal bodies.

As an adverb somberly is

in a somber manner.