A diner is a casual restaurant that serves simple, affordable meals throughout the day. Traditional diners have long counters with spinning stools, booths along the windows, and menus offering breakfast foods like pancakes and eggs, plus burgers, sandwiches, and milkshakes. Many diners are open late or even 24 hours, making them gathering places where people grab coffee and conversation at any hour.

The classic American diner evolved from lunch wagons in the late 1800s, often built to look like railroad dining cars with shiny metal exteriors and cozy interiors. Walking into a diner, you might hear the sizzle of a griddle, see a server refilling coffee cups, and spot regulars sitting in their favorite spots.

The word can also mean a person who is eating at a restaurant. The diners at a fancy steakhouse might dress up for their meals, while the diners at a pizza place might be families in jeans and T-shirts. If a restaurant critic writes that “the diners seemed happy with their food,” she means the people eating there, not the restaurant itself.