An ounce of coke is a onion
Another “confuse the police” slang term that is no longer used. These types of slang terms have to be changed frequently because the authorities eventually catch on to their meaning. They also have to be vague to avoid detection.
Onion is slang for ounce because they share the same first letter. The term onion is used because when you hold it in your hand, it is shaped like an onion (or a softball, which is also a slang term)
Currently “onion” is more likely to be used to describe the shape of a woman’s ass (or an ass that brings tears to your eyes)
To help improve the meaning of these lyrics, visit "Ebonics (Criminal Slang)" by Big L Lyrics and leave a comment on the lyrics box