folly folly /ˈfɑːli/

noun

1. () The trait of acting stupidly or rashly  ( unwiseness , folly , foolishness )
   the trait of acting stupidly or rashly
   
2. () A stupid mistake  ( betise , foolishness , imbecility , folly , stupidity , bêtise )
   a stupid mistake
   
3. Foolish or senseless behavior  ( craziness , folly , foolery , indulgence , lunacy , tomfoolery )
   foolish or senseless behavior
   
4. The quality of being rash and foolish  ( craziness , folly , foolishness , madness , nuttiness [Informal] )
   the quality of being rash and foolish
    Trying to drive through a blizzard is the height of folly
   trying to drive through a blizzard is the height of folly
    Adjusting to an insane society is total foolishness
   adjusting to an insane society is total foolishness