lu·na·cy 
/ˈlu:nəsi/ noun
/ˈlu:nəsi/ noun [noncount] 1 a : extreme foolishness
▪ Quitting her job was an act of sheer/pure lunacy. [=madness]
b : something that is very foolish
▪ Quitting her job was lunacy. ▪ It would be lunacy [=madness] to try driving home in this storm. ▪ His idea was considered total/sheer/complete lunacy. 2 old-fashioned : extreme mental illness : insanity
▪ Quitting her job was an act of sheer/pure lunacy. [=madness]
b : something that is very foolish
▪ Quitting her job was lunacy. ▪ It would be lunacy [=madness] to try driving home in this storm. ▪ His idea was considered total/sheer/complete lunacy.
