Definition (drinks)
In a bar setting, it refers to refusing further service of alcoholic beverages to a patron, often because they appear to have consumed too much.
The bartender saw he was too intoxicated and decided to cut him off from any more drinks.
As he was causing a scene at the bar, the waiter promptly cut him off from his next drink.
If patrons behave inappropriately in a bar, the staff have the right to cut them off from alcohol sales.