|She's not a soldier, she's not Indian, but she's definitely doolally|
(photo by Holly Clark)
Adjective. Slang (originally military). Early 20th century.
[Deolali, a town near Bombay.]
Originally (now less usual) doolally tap [Urdu from Persian tap fever].
Temporarily insane; deranged; feeble-minded, simple, foolish.
For those unfamiliar with this rather delightful Britishism, doolally means a bit nuts, crazy, bonkers, and so forth, and is accompanied by a fittingly loopy etymology. Deolali is a town near Bombay, India, and it was a staging point for British colonial troops arriving to and leaving from the continent. As well as the military post, Deolali also housed a sanatorium, and it is said that soldiers barracked there (and particularly those who were waiting to absquatulate back to Blighty) would go a bit doolally tap - that is, a bit nuts.
You don't really hear doolally tap anymore, but to say that someone has gone a bit doolally is still well understood throughout Britain. I never found out if Mum did make her little bêtise, but considering that she was a bit doolally herself, I rather think (and hope) that she did.
Do please billet your loopiest comments in the barrack-box below.