tearfulness vs sadness

tearfulness and sadness both are nouns.

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

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

Other hypernyms of tearfulness include unhappiness.

tearfulness (noun)	sadness (noun)
sadness expressed by weeping	the quality of excessive mournfulness and uncheerfulness
	emotions experienced when not in a state of well-being
	the state of being sad