#1 folly n. [foolishness, unwiseness] the trait of acting stupidly or rashly. wn
#2 folly n. [stupidity, betise, foolishness, imbecility] a stupid mistake. wn
#3 folly n. [foolishness, craziness, madness] the quality of being rash and foolish; "trying to drive through a blizzard is the height of folly"; "adjusting to an insane society is total foolishness". wn
#4 folly n. [foolery, tomfoolery, craziness, lunacy, indulgence] foolish or senseless behavior. wn
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