Diner definition

Agent noun of dine; one who dines; one who eats a meal, especially dinner.

When it comes to Chinese food I have always operated under the policy that the less known about the preparation the better. A wise diner who is invited to visit the kitchen replies by saying, as politely as possible, that he has a pressing engagement elsewhere. –Calvin Trillin
A small and inexpensive type of restaurant which is modelled to resemble a dining car.
A railroad dining car.

The diner is everybody's kitchen. –Richard Gutman