cheerlessness vs sadness

cheerlessness and sadness both are nouns.

Word	Noun	Adjective	Verb	Adverb
cheerlessness	Yes	No	No	No
sadness	Yes	No	No	No

As nouns, sadness is a hypernym of cheerlessness; that is, sadness is a word with a broader meaning than cheerlessness:

Other hypernyms of cheerlessness include unhappiness.

cheerlessness (noun)	sadness (noun)
a feeling of dreary or pessimistic sadness	the quality of excessive mournfulness and uncheerfulness
	emotions experienced when not in a state of well-being
	the state of being sad