hollowness vs untruthfulness

hollowness and untruthfulness both are nouns.

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

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

hollowness: the quality of not being open or truthful; deceitful or hypocritical
untruthfulness: the quality of being untruthful

hollowness (noun)	untruthfulness (noun)
the property of having a sunken area	the quality of being untruthful
the quality of not being open or truthful; deceitful or hypocritical
the state of being hollow: having an empty space within