Ridiculousness is a related term of childishness.
In uncountable|lang=en terms the difference between ridiculousness and childishness
is that ridiculousness is (uncountable) the characteristic of being ridiculous while childishness is (uncountable) the state or characteristic of being childish.
In countable|lang=en terms the difference between ridiculousness and childishness
is that ridiculousness is (countable) the result of being ridiculous while childishness is (countable) childish behaviour.
As nouns the difference between ridiculousness and childishness
is that ridiculousness is (uncountable) the characteristic of being ridiculous while childishness is (uncountable) the state or characteristic of being childish.
ridiculousness
English
Noun
(uncountable) The characteristic of being ridiculous.
(countable) The result of being ridiculous.
Synonyms
* ridiculosity (less common)
childishness
English
Noun
(uncountable) The state or characteristic of being childish.
(countable) Childish behaviour.
See also
* puerilism
* puerility