folly vs stupidity

folly and stupidity both are nouns.

Word	Noun	Adjective	Verb	Adverb
folly	Yes	No	No	No
stupidity	Yes	No	No	No

As nouns, folly and stupidity are synonyms defined as:

Other synonyms of folly include betise, foolishness, imbecility.

As nouns, stupidity is a hypernym of folly; that is, stupidity is a word with a broader meaning than folly:

folly (noun)	stupidity (noun)
foolish or senseless behavior	a stupid mistake
a stupid mistake	a poor ability to understand or to profit from experience
the trait of acting stupidly or rashly
the quality of being rash and foolish