absurdity vs ridiculousness

absurdity and ridiculousness both are nouns.

Word	Noun	Adjective	Verb	Adverb
absurdity	Yes	No	No	No
ridiculousness	Yes	No	No	No

As nouns, absurdity and ridiculousness are synonyms defined as:

absurdity and ridiculousness: a message whose content is at variance with reason

Other synonyms of absurdity include absurdness.

absurdity (noun)	ridiculousness (noun)
a ludicrous folly	a message whose content is at variance with reason
a message whose content is at variance with reason