Green’s Dictionary of Slang

basuco n.

also basuko, bazuca, bazuco
[Colombian Sp., + ? links to Sp. bazucar, to shake violently or basura, waste, rubbish; a parallel ety. suggests the SE bazooka, with a ref. to the drug’s ‘explosive’ effect]

(drugs) coca paste, part of the process that produces cocaine, mixed with a variety of impure and poss. toxic substances, e.g. leaded gasoline, kerosene, sulphuric acid and potassium permanganate; smoking basuco as a ‘cigarette’ (mixing basuco either with tobacco or marijuana) is common in cocaine-producing countries.

[US]Wall Street Journal 28 Nov. 35/2: Colombia has discovered a problem of drug abuse in its own backyard. A cigarette called basuco is appearing on the streets.
C. Nicholl Fruit Palace 67: There’s a big internal market: a lot of coke and basuko used by the street boys.
The Word and I (Wash.) I 59: The current favorite is a drug called bazuco, similar to the ‘crack’ that is epidemic in some US cities.
[US]T. Williams Crackhouse 74: ‘I thought bazuca was the residue when they make freebase,’ he says, ‘and con-con was just about the same thing.’.
R. Kirk Generation under Fire 5: Bazuco, the highly addictive residue left from the fabrication of cocaine.
[US]H. Abadinsky Drug Abuse 105: Because it requires less processing than cocaine, coca paste — called bazuco — is popular among low-income groups in these countries.
[US]ONDCP Street Terms 2: Basuco (Spanish) — Cocaine; Coca paste residue sprinkled on regular or marijuana cigarette.
K. Koonings Armed Actors 12: So-called chichipato gangs (small gangs without even decent weaponry) rob stores, homes, vehicles and pedestrians in the poor barrios, using bazuco, a potent coca base, as their daily stimulant.