Green’s Dictionary of Slang

C n.3

also cee

1. (drugs) cocaine.

[US]S.F. Call 27 Nov. 3/1: Among fiends, the drug [...] might be called just ‘C’ as morphine is called ‘M’ or ‘white stuff’.
[US]F. Williams Hop-Heads 17: The table was littered with [...] the ‘bindles’ (packages) of ‘c’ (cocaine).
[Aus]Truth (Brisbane) 22 June 12/5: ‘In my experience, nine out of 10 use cocaine or heroin, or ‘C’ and ‘H’ as the professional slang goes.
[US]J. Tully Shadows of Men 189: He knew that an addict ‘loaded on C’ was subject to wild and painful imaginings.
[US]W. Burroughs letter 24 July in Harris (1993) 3: Where do you secure the C? My own supply is utterly depleted.
[US]W. Brown Monkey On My Back (1954) 73: Of the two he vastly preferred cocaine but frequently used heroin because ‘C’ is hard to get.
[US] ‘Do You Know What It Means?’ in D. Wepman et al. Life (1976) 158: Do you know what it means to have a supply of C and a supply of horse, / Not to need any connections because you’re the big boss.
[US]E. Droge Patrolman 167: Whether you call it snow, sugar, dust, coke, C, candy, girl, or Charlie, it’s still cocaine.
[US]D.E. Miller Bk of Jargon 337: C: Cocaine.
[US](con. 1986) G. Pelecanos Sweet Forever 11: When he did high-grade C with Donna the two of them could go half the night.
[US]ONDCP Street Terms 5: C — Cocaine.
[US]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’.

2. (US Und. ) constr. with the, the occupation of confidence trickery.

[US]L. Block ‘Badger Game’ in One Night Stands (2008) 29: ‘I’m working the C out of Philly’ [...] meant [...] that he was a confidence man who started originally in Philadelphia.

3. as the C, methcathinone.

[US]ONDCP Street Terms 21: The C — Amphetamine; methcathinone.