Green’s Dictionary of Slang

phut adv.

In phrases

go phut (v.) (also go pfft) [echoic of the noise of air escaping from a deflated, popped balloon]

to come to an abrupt end; spec., of a couple, to divorce.

1888		Kipling Story of Gadsbys (1889) 55: The whole thing went phut. She wrote to say that there had been a mistake.
1894		Civil & Milit. Gaz. (Lahore) 18 Oct. 4/3: If we wos [i.e. generals] — where’ your army? — Gone fut.
1925		Wodehouse Carry on, Jeeves 138: Biffy, the poor spineless fish, had lost his nerve. My closely reasoned scheme had gone phut.
1929		W. Winchell On Broadway 3 Sept. [synd. col.] Larry Kent and June Collyer have phffft.
1930		(con. 1914–18) Brophy & Partridge Songs and Sl. of the British Soldier 128: Gone Phutt.—Crashed, collapsed, lost favour.
1934		Wodehouse Right Ho, Jeeves 80: Uncle Tom would see a hundred Milady’s Boudoirs go phut rather than take the rap.
1936		L. Pound ‘American Euphemisms for Dying’ in AS XI:3 198: Went pfft.
1961		W.R. Burnett Round the Clock at Volari’s, 10: She was one of the reasons his marriage had gone pffft.
1999		Guardian 2 July 21: The microphones had gone phut.
2023		(con. 1962) J. Ellroy Enchanters 9: She says rough-trade boys abducted her [...] She glommed brief headlines and saw it go pffft.

In exclamations

get phut!

(Aus.) a euph. for get fucked! excl.

1960

J. Iggulden Storms of Summer 297: ‘Cut the big talk,’ said Charles contemptuously. ‘Ah . . . get phut!’ said Bluey carelessly.