foolishness vs betise

foolishness and betise both are nouns.

Word	Noun	Adjective	Verb	Adverb
foolishness	Yes	No	No	No
betise	Yes	No	No	No

As nouns, foolishness and betise are synonyms defined as:

Other synonyms of foolishness include folly, imbecility, stupidity.

foolishness (noun)	betise (noun)
a stupid mistake	a stupid mistake
the trait of acting stupidly or rashly
the quality of being rash and foolish