Green’s Dictionary of Slang

bo n.3

[abbr. Colombo]

(US drugs) Colombian marijuana.

[US] in Spears Sl. and Jargon of Drugs and Drink (1986).
[US]T.R. Houser Central Sl.
[US]K. Scott Monster (1994) 228: ‘You smoke cigarettes?’ ‘Naw, just bo.’.
[US]ONDCP Street Terms 4: Bo — Marijuana.