Foolishness is a synonym of preposterousness.
As nouns the difference between foolishness and preposterousness
is that foolishness is (uncountable) the state of being foolish while preposterousness is the quality of being preposterous.
foolishness
Noun
(uncountable) The state of being foolish.
(countable) A thing or event that is foolish, or an absurdity.
Synonyms
* imprudence, folly
* extravagance, irresponsibility
* indiscretion, absurdity
* ridiculousness
* stupidity
Antonyms
* wisdom
Related terms
* fool