gloominess vs sombreness

gloominess and sombreness both are nouns.

Word	Noun	Adjective	Verb	Adverb
gloominess	Yes	No	No	No
sombreness	Yes	No	No	No

As nouns, gloominess and sombreness are synonyms defined as:

Other synonyms of gloominess include gloom, somberness.

gloominess (noun)	sombreness (noun)
the quality of excessive mournfulness and uncheerfulness	a manner that is serious and solemn
The property of having a frowning or scowling appearance.	a feeling of melancholy apprehension
a feeling of melancholy apprehension	a state of partial or total darkness
an atmosphere of depression and melancholy