Usually used in the sense that there is no real food to eat, but people will be content drinking alcoholic beverages without the intentions of eating something.

Commonly used before one might go off to a party but they have no concrete dinner plans.
"Hey man, so you bringing any food up? We can barbeque a steak or something when you get here."

"No, that's okay, man. I think we'll just have some liquid dinner."
by praine August 11, 2009
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