A restaurant or coffee shop you half remember visiting while drunk. In most cases the location of the restaurant is mistaken. If a drunk forgets something and tries to retrieve it the following day it will seem as though the restaurant was an apparition, as there is no restaurant where they believe they ate.

Its called a phantom diner because the scenario is very similar to a popular ghost story genre - a man has en experience with strange characters at a bar, on a ship, on a train, only to return the next day to find the setting has been abandoned for many years, or is just gone.
"I swear I was at a diner on 45th and Oak Street last night and left my phone. I took a cab there this morning, but when I got there there was no restaurant to be found. It's like it just vanished"

"You were at a phantom diner"
by Pellar December 31, 2009
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