sombreness

(noun) a state of partial or total darkness. Synonyms: gloom, somberness. Example: "He struck a match to dispel the gloom."

(noun) a feeling of melancholy apprehension. Synonyms: gloom, gloominess, somberness.

(noun) a manner that is serious and solemn. Synonyms: graveness, gravity, sobriety, soberness, somberness.