Green’s Dictionary of Slang

1. (also big D) dilaudid.

1954		Maurer & Vogel Narcotics and Narcotic Addiction.
1977		L. Young et al. Recreational Drugs.
1981		D.E. Miller Bk of Jargon 337: D: Dilaudid.
1992		Bentley & Corbett Prison Sl. 69: D’s The most common name for Dilaudid [...] a synthetic, pharmaceutically produced opiate closely resembling heroin.
2023		(con. 1962) J. Ellroy Enchanters 147: I pulled out a vial of four-grain Dilaudid [and] popped two big ‘D’’s.

2. heroin [duji n.].

2010

Codella and Bennett Alphaville (2011) 12: ‘So, a little C or D sometimes?’ [...] ‘Yeah,’ he says, ‘I like coke, but [...] I’m not a dope addict’.

3. LSD.

1971		Illinois Legislative Investigating Committee Drug Crisis in Spears (1986).
2001		ONDCP Street Terms 7: D — LSD.

4. (drugs) phencyclidine [angel dust n.].

1979		H. Feldman et al. Angel Dust 144: He would smoke ‘D’ and get an ax and he chopped somebody’s car up.
2001		ONDCP Street Terms 7: D — [...] PCP.

5. cannabis [dope n.¹ (7)].

2008		Urban Dict. 7 Oct. 🌐 D Another term for Cannibis [sic] [...] A shorter term for the term ‘draw’, another word popular amongst drug users.
2017		SL ‘Tropical’ 🎵 Don't think that this shit comes cheap / So bitch don't moan / When I charge 15 for a D.