Green’s Dictionary of Slang

pop adv.

In phrases

go pop (v.)

1. to die.

1880		Henley & Stevenson Deacon Brodie III tab.V ii: One more of my boyhood’s dreams gone pop.
1901		B. Pain De Omnibus 51: Some art-of-the-way furrin prince ’ad gone pop.
1899		H. Champion ‘On Top’ 🎵 When help arrived, I was very near going off pop’.

2. to lose one’s temper.

1905		Sun. Times (Perth) 10 Sept. 4/7: She went off pop like a flash in the pan. ‘You wretch! you horrid! you vulgar man!’.
1912		Bulletin (Sydney) 28 Nov. 26: Australia: ‘Well, I’m jiggered! Here am I paying good money to travel along certain lines in a stipulated direction, while you’ — / The Engine’s Crew: ‘Don’t go pop, Mister. How can we know who’s to do the driving unless we play these games out?’.
1917		Rising Sun 8 Feb. 4/2: Does the O.C. ever go off pop, if your boots are not cleaned?