Blue-plate special

A blue-plate special is a discount-priced meal that changes daily. The practice was common from the 1920s in American and Canadian restaurants through the 1950s, especially in diners and greasy spoons. As of 2007, there are still a few restaurants and diners that offer blue-plate specials under that name, sometimes on blue plates, but it is a vanishing tradition.

A collection of 1930s prose gives this definition: "A Blue Plate Special is a low-priced daily diner special — a main course with all the fixins, a daily combo, a square for two bits."