doolally

1. (originally military slang) Eccentric; insane, mad.Examples: ""Will you write me an Essay on Corsets?" / "On what?" I asked incredulously—knowing that he had been a distinguished soldier, and suspecting that he had suddenly developed what the soldiers describe as "a touch of the doolally.""; ""When you've got any God's amount of brains," said Frobisher, "you can pretend to be doolally;[…]""; "Doolally tap. It's the strain see – and it gets the doolally lads first."Synonyms: doolally tap, 5150, bananas, barking, barking mad, buggish, buggy, bughouseIrelandUKslang

2. (by extension) Carried away by enjoyment, excitement, etc.Examples: "You are there to entertain. Education is something we like doing. That's not actually the biggest thing on the night, when people are queuing to get in and paying their money. They want to go doolally to their favourite records."; "'I've never had a pet before,' Darkus gazed happily at Baxter [a beetle]. 'Thank you.' / 'That's all right, lad.' Uncle Max threw his hands up in defeat. 'I can hardly say no, when I know Barty would say yes.' / Darkus looked up, surprised. 'He would?' / 'Of course! A handsome hexapod like this? He'd be doolally about it!'"; "Australia went doolally for the visit: the Queen [Elizabeth II] waved away flies in 57 towns over 58 days; inspected an endless row of sheeps' arses in Wagga; ate Australia-shaped sandwiches with Vegemite borders at a reception in Rockhampton; and said hello to a bedridden woman in Hobart who was trundled four miles for the meeting."IrelandUKbroadlyslang