It depends what is in the glass. See alcohol
In so many films and TV shows people are shown with a glass in their hands. Also at weddings and parties it is the same, people wandering around drinking alcohol. Alcohol is a known poison and health risk, it is also a downer, its action is to make one less aware. But for many people holding a glass can represent good times, friendship, intimacy – or drunkenness and death of sexual feelings.
It can also for some represent making money. The profits on selling alcohol is significant.
Empty Drinking Glasses: Past events; memories.
Useful questions and hints:
What do you associate with holding a glass?
What memories are there for you in the glass?
What is the theme of the dream?