robustness vs lustiness

robustness and lustiness both are nouns.

Word	Noun	Adjective	Verb	Adverb
robustness	Yes	No	No	No
lustiness	Yes	No	No	No

As nouns, robustness and lustiness are synonyms defined as:

robustness and lustiness: the property of being strong and healthy in constitution

Other synonyms of robustness include hardiness.

robustness (noun)	lustiness (noun)
the property of being strong and healthy in constitution	the property of being strong and healthy in constitution
the characteristic of being strong enough to withstand intellectual challenge