gloominess vs gloom

gloominess and gloom both are nouns.

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

As nouns, gloominess and gloom are synonyms defined as:

Other synonyms of gloominess include somberness, sombreness.

As nouns, gloominess and gloom are synonyms defined as:

Other synonyms of gloominess include glumness.

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