Green’s Dictionary of Slang

1. (also brown bomb) a laxative pill.

c.1943		‘Bill O. Lading’ You Chirped a Chinful!! n.p.: Brown Bombs: C.C. pills, the army laxative.
1965		D. Pearce Cool Hand Luke (1967) 72: Luke had Carr ask the Wicker Man for a couple of Brown Bombers and a cup of Epsom salts.
1971–2		C. Shafer ‘Catheads [...] and Cho-Cho Sticks’ in Abernethy Bounty of Texas (1990) 199: brown bombs, n. – laxatives.

2. (Aus., Sydney) a parking police officer.

1953		Sydney Morning Herald 3 Jan. 6/2: ‘Brown bombers’, Sydney parking police, probably derived from the colour of their uniforms and influenced by the use of ‘bomb’ for an old car.
1968		D. Ireland Chantic Bird 61: A brown bomber—a parking cop—gave me a fright.
1985		R.G. Barrett You Wouldn’t Be Dead for Quids (1989) 28: I’m double parked and it’s swarming with friggin’ brown bombers out there.
1993		Aus. Word Map 🌐 brown bomber. a parking inspector. Compare grey bomber, grey ghost, blue bomber, sticker licker. [from the brown colour of their uniform (now grey or blue)] [...] ‘Now that the brown bombers have had a uniform change, it is my understanding that they had been re-named as grey ghosts’.
2003		P. Carey My Life as a Fake 249: Threatening and pushing like a parking cop – brown bombers, we used to call them.

3. (N.Z.) DB (Dominion Breweries) brown ale.

1952		Here and Now Jan. 15: But he [barman] missed one clink, and counted wrong, and felt wild because someone had pinched a bottle of the brown bomber, and it wasn’t him this time [DNZE].
1968		N.Z. Contemp. Dict. Supplement (Collins) 4: brown bomber n. (Coll.) name given-in N.Z., beer [DNZE].

4. (drugs) strong (20mg) capsules of amphetamine, usu. coloured brown.

1969		R.R. Lingeman Drugs from A to Z (1970) 51: brown bomber (1) [from the colour] usually durophet-m capsules.
1979		S. King Dead Zone (1980) 77: There was nothing heavy in his dope stash—two Brown Bombers was the heaviest.

5. LSD.

2001

ONDCP Street Terms 4: Brown bombers — LSD.