stuffiness vs somberness

stuffiness and somberness both are nouns.

Word	Noun	Adjective	Verb	Adverb
stuffiness	Yes	No	No	No
somberness	Yes	No	No	No

As nouns, somberness is a hypernym of stuffiness; that is, somberness is a word with a broader meaning than stuffiness:

Other hypernyms of stuffiness include graveness, gravity, soberness, sobriety, sombreness.

stuffiness (noun)	somberness (noun)
dull and pompous gravity	a manner that is serious and solemn
the quality of being close and poorly ventilated	a feeling of melancholy apprehension
state of obstruction or stoppage or air in the nose or throat	a state of partial or total darkness