absurdity vs meaninglessness

absurdity and meaninglessness both are nouns.

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

As nouns, meaninglessness is a hypernym of absurdity; that is, meaninglessness is a word with a broader meaning than absurdity:

Other hypernyms of absurdity include bunk, hokum, nonsense, nonsensicality.

absurdity (noun)	meaninglessness (noun)
a ludicrous folly	the quality of having no value or significance
a message whose content is at variance with reason	a message that seems to convey no meaning