hollowness vs emptiness

hollowness and emptiness both are nouns.

Word	Noun	Adjective	Verb	Adverb
hollowness	Yes	No	No	No
emptiness	Yes	No	No	No

As nouns, emptiness is a hypernym of hollowness; that is, emptiness is a word with a broader meaning than hollowness:

hollowness (noun)	emptiness (noun)
the property of having a sunken area	the quality of being valueless or futile
the quality of not being open or truthful; deceitful or hypocritical	an empty area or space
the state of being hollow: having an empty space within	the state of containing nothing
	having an empty stomach