Green’s Dictionary of Slang

O n.

[abbr.]

1. [1930s+] (US drugs, also oh) an ounce of a narcotic.

2. [1930s+] (drugs) opium.

3. [1980s+] (US drugs) a $50 rock of cocaine.

4. [2010s+] (US drugs) an ounce of cannabis.

In compounds