Meaning and local context
In New Orleans, “go cup” means A disposable cup used to carry a drink away from a venue. A practical New Orleans nightlife term shaped by local alcohol rules.
Example in context
A local example is “Ask for a go-cup before you leave.” In plain English, that means “Ask for a takeaway cup before you leave.”
Ask for a go-cup before you leave.
Ask for a takeaway cup before you leave.
How to interpret it
The surrounding sentence is important when interpreting “go cup”. Use the regional sense above when the situation matches the example instead of relying on the word or phrase in isolation.
Tone and caution
Alcohol laws vary by place and event; the term is not permission by itself. Because this is informal regional language, tone and situation should guide whether you use “go cup” yourself or simply recognise it when someone else uses it.