precocious vs precociousness

precocious is not a noun while precociousness is a noun.

Word	Noun	Adjective	Verb	Adverb
precocious	No	Yes	No	No
precociousness	Yes	No	No	No

precocious (noun)	precociousness (noun)
	intelligence achieved far ahead of normal developmental schedules

precocious (adjective)	precociousness (adjective)
characterized by or characteristic of exceptionally early development or maturity (especially in mental aptitude)
appearing or developing early