A zip of marijuana is slang for an ounce.
I never knew the terminology until I moved to a recreational marijuana state.
I was living down south where recreational marijuana isn’t legal. If I wanted to buy an ounce of marijuana from a guy on the street, I was going to pay about $200. The cost for that ounce of marijuana in the dispensary was even higher because the state only allowed medical sales. After I moved to the West coast, I started using even more recreational marijuana products. They were much easier to find and obtain. I met a couple of guys this week when I went fishing at the reservoir. I was there most of the day in my kayak and there were some other guys there too. They were smoking marijuana on the side of the water and I pulled up my kayak next to them to see if they had some buds that they could offer to me. One of the guys named Jack gave me a joint and I sat and talked with the guys while all of us smoked marijuana. The guy told me that he could offer me a zip of marijuana for $75. When I found out that it was the same marijuana that we were smoking, I was ready to give the guy cash. I had $75 in my wallet, thankfully. I didn’t have to go to an ATM or leave the area. I told the guy that I would happily take a zip of marijuana for 75 bucks. Before the guy left the lake that day, I got a fat sack of marijuana and the guy’s phone number so I can call him next time I need weed.