a building where people go to eat
"The family gathered at their favorite restaurant for dinner last night."
An eating establishment in which diners are served food, usually by waiters at their tables but sometimes (as in a fast food restaurant) at a counter.
"We decided to grab dinner at the new Italian restaurant downtown where our meal was brought right to our table by a waiter."
In plain English: A restaurant is a place where you go to eat meals that are prepared and served by someone else for money.
"We decided to eat dinner at the Italian restaurant on Main Street."
Usage: A restaurant is an eatery where customers sit to be served meals, typically by staff at the table rather than ordering from a menu board or counter like in casual dining spots. Use this term for full-service establishments instead of generic words like "diner" when emphasizing formal seating and waiter service.
The word comes from the French term restaurant, which originally referred to a "restorative" soup. This name was chosen because it was believed to restore health and energy to those who ate it at the first dining establishments.