smallness vs petiteness

smallness and petiteness both are nouns.

Word	Noun	Adjective	Verb	Adverb
smallness	Yes	No	No	No
petiteness	Yes	No	No	No

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

smallness (noun)	petiteness (noun)
the property of having a relatively small size	the property of being very small in size
lack of generosity in trifling matters
the property of being a relatively small amount
the property of having relatively little strength or vigor
The quality of being minor in influence, power, or rank.