What is the name of a small unluxurious restaurant?

Is there a name for this kind of restaurant? Searching Google, I can't find any synonym of restaurant. I've tried to search for images of unluxurious restaurant, small restaurant or mundane restaurant, with no satisfactory result. The restaurant I'm looking for is small, not so clean and definitely not a place that high class people go to eat.

It can be a house:

Or lie on a side of the street:

Solution 1:

"Hole in the wall"?

Here's the definition from Oxford Dictionaries:

hole in the wall 1. chiefly North American A small dingy place, especially a bar or restaurant

Another definition from English Daily:

Definition A small, simple place, particularly a shop or restaurant

Example Let's go to the Italian restaurant on Smith Street. It's just a hole in the wall, but the food is excellent.

Etymology This phrase has been used since the early 1800s. A 'hole' is an empty space, and a 'wall' is part of a building. So a 'hole in the wall' is a simple, undecorated space in a building.

Note that today it is almost always used about food establishments; less so about shops.

Solution 2:

In the UK (and apparently in the USA according to Wikipedia) we often use the term 'greasy spoon cafe' (or just 'greasy spoon') to refer to a small, grubby, generic eaterie of the not-salubrious kind.

The name "greasy spoon" is a reference to the typically high-fat, high-calorie menu items such as eggs and bacon. The term has been used to refer to a "small cheap restaurant" since at least the 1920s [my italics]

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