Green’s Dictionary of Slang

1. (US campus) a form of cheer, mimicking the firing, flight and explosion of a fireworks ‘rocket’, which accompanies a tiger n. (2)

1868

Sportsman 18 Nov. 2/1: Notes on News [...] [from US paper] Proposed three cheers, which were given with will, followed the usual ‘tiger’ and ‘rocket.’ It (the rocket) is given with f-z-r-z-boom-a-h! The first exclamation is supposed to imitate the flight of a rocket in the air; the second the explosion, and the third the admiring exclamations of the enthusiastic spectators as they witness the burst of coloured fire.

2. (orig. milit.) a severe reprimand or telling off; thus get a rocket, give a rocket.

1941		New Statesman 30 Aug. 218/3: To stop a rocket, receive a reprimand.
1946		G. Gibson Enemy Coast Ahead (1955) 240: Try and avoid going over towns and aerodromes and not to beat up policemen [...] because they’ll get a rocket if they do.
1989		Dandy Comic Library No. 142 7: Aunt Aggie often gives you a rocket for being untidy!
1993		B. Moore Lex. of Cadet Lang. 91: usage: ‘He’s going to cop a rocket for that security breach.’.
2002		E.P. Rich House of Eliott: the Anxious Years 15: But father gave me a rocket about jumping jobs in so short a period. It was bad for my record.
2012		(con. 1943) G.S. Manson Coorparoo Blues [ebook] [He] got a very serious rocket under him from the inspector.

3. (drugs) a marijuana cigarette [one ‘blasts’ off].

1942		Berrey & Van den Bark Amer. Thes. Sl.
1953		Anslinger & Tompkins Traffic In Narcotics 314: rockets. Marihuana cigarettes.
1978		L. Kramer Faggots 308: I’ve got rockets, Dinky’s got sparklers, and that will have to do.
2001		ONDCP Street Terms 18: Rockets — Marijuana cigarette.
2016		A. Wheatle Crongton Knights 3: Gs spent their time smoking rockets in parked cars.

4. (US black) a bullet.

1964		R. Abrahams Deep Down In The Jungle 135: If you don’t believe it, look at those motherfucking rockets in his god damn head.
1965		B. Jackson Get Your Ass in the Water (1974) 47: I pumped six a my rockets [bullets] in his motherfucken chest.

5. (Aus.) a modified automobile, geared to speed and visual ostentation, a hot-rod n. (2)

1964

‘Charles Barrett’ Address: Kings Cross 74: They could make a mouse spit at a cat, or a car-crazy kid steal someone’s rocket and run it over a cliff.

6. (N.Z. prison) amphetamine.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 155/1: rocket n. = speed sense 1.