Green’s Dictionary of Slang

zol n.

also zoll
[ety. unknown; zol is recorded as 1950s US/Mex. border drug use, but no provable link exists; Branford, Dict. of South African English (4th edn, 1993) notes the obs. trade name of miniature cheroots but gives no date; if it precedes drug use it would be an obvious root]
(S.Afr. drugs)

1. a hand-rolled cigarette.

[SA]H.C. Bosman Cold Stone Jug (1981) II 28: The dagga-cigarette is now ready (the ‘zol’, they call it) and the rokers gather round in a circle.
[SA]H. Levin Bandiet 153: If he ever joined a group, it was to bum some tobacco, roll a quick zoll then head off.
[UK]G. Kente Too Late in Kavanagh S. Afr. People’s Plays (1981) 117: (Offside is making a tobacco zol) offside: A smoke, Sadu?
[SA]A. Brink Rights of Desire (2001) 270: What she brought to the study was [...] a dagga zol.

2. a marijuana cigarette.

Drum (Johannesburg) Apr. in Freed (1963) 122: He was given a ‘zol’ of dagga to smoke, and when he had become totally drugged he was robbed and beaten up.
[SA]J. Matthews The Park and Other Stories (1983) 22: ‘Jammie, yer any dagga on yer?’ [...] ‘Here. Roll two zolls.’.
[SA]A. Fugard Tsotsi 20: The zol passed between Butcher and Die Aap. They took sharp, deep drags, smoking with a quiet intensity.
[US]ONDCP Street Terms 23: Zol — Marijuana cigarette.

3. a measure of marijuana, enough to make a single cigarette.

[SA]cited in J. & W. Branford Dict. S. Afr. Eng. (1991).
Weekend Post 13 June 3: The dagga is packed into 2g to 4g ‘zols’ or envelopes.

4. cannabis; also attrib.

[UK]J.M. Meiring Candle in the Wind 132: They called him ‘Zoll Plaatjies.’ He was a big business. It was not a question of a few ounces of dagga.
[SA]B. Simon ‘Outers’ Born in the RSA (1997) 75: He’s got this farm [...] and Pietie’s got this plan [to] grow zol, the best . . . rooibard, poisons, Malawi gold, Thai.
[SA]B. Simon ‘Score Me the Ages’ Born in the RSA (1997) 135: So captain, where’s my birthday zoll?
[SA]R. Malan My Traitor’s Heart (1991) 47: He drank and smoked zol – dope. [Ibid.] 70: You could buy zol on almost any roadside.
[SA]A. Lovejoy Acid Alex 51: He had other names for dagga like [...] zol and boom.
[SA]Mail & Guardian (Johannesburg) 31 Oct. [Internet] Zuma did smoke ‘zol’, but it wasn’t dagga.

In compounds

zol monkey (n.)

a habitual smoker of cannabis.

[SA]Mail & Guardian (Johannesburg) 24 Sept. [Internet] No, I am not a zol monkey. This is not a throwdown from a bonghead.