doolally
Concise Oxford English Dictionary © 2008 Oxford University Press:
doolally /duːˈlali/
▶adjective Brit. informal temporarily insane.
– origin 1920s: orig. doolally tap, Indian army sl., from Deolali (a town near Bombay) + Urdu tap ‘fever’.
'doolally' also found in these Oxford entries:

