smartness vs nattiness

smartness and nattiness both are nouns.

Word	Noun	Adjective	Verb	Adverb
smartness	Yes	No	No	No
nattiness	Yes	No	No	No

As nouns, nattiness is a hyponym of smartness; that is, nattiness is a word with a more specific, narrower meaning than smartness:

Other hyponyms of smartness include dapperness, jauntiness, rakishness.

smartness (noun)	nattiness (noun)
elegance by virtue of being fashionable	stylishness as evidenced by a smart appearance
liveliness and eagerness
intelligence as manifested in being quick and witty
a kind of pain such as that caused by a wound or a burn or a sore