childishness vs puerility

childishness and puerility both are nouns.

Word	Noun	Adjective	Verb	Adverb
childishness	Yes	No	No	No
puerility	Yes	No	No	No

As nouns, childishness and puerility are synonyms defined as:

childishness (noun)	puerility (noun)
a property characteristic of a child	a property characteristic of a child
	the state of a child between infancy and adolescence