gloomy vs gloominess

gloomy is not a noun while gloominess is a noun.

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

gloomy (noun)	gloominess (noun)
	the quality of excessive mournfulness and uncheerfulness
	The property of having a frowning or scowling appearance.
	a feeling of melancholy apprehension
	an atmosphere of depression and melancholy

gloomy (adjective)	gloominess (adjective)
depressingly dark
filled with melancholy and despondency
causing dejection