idiocy

 
Pronunciation: /ˈɪdɪəsi/

noun (plural idiocies)

[mass noun]
  • extremely stupid behaviour: the idiocy of decimating yew forests [count noun]: every aspect of public administration throws up its own idiocies

Origin:

early 16th century (originally denoting low intelligence): from idiot, probably on the pattern of pairs such as lunatic, lunacy