hole in the wall
noun [ C usually singular ] uk/ˌhəʊl ɪn ðə ˈwɔːl/ us/ˌhoʊl ɪn ðə ˈwɑːl/
(MONEY)
UK（cash machine的非正式说法）
informal for cash machine mainly UK
(BUILDING)
US小商店;小餐馆;狭小的房子
a small, often unpleasant, shop, house, or restaurant
It's just a hole in the wall but the food is good. 虽说只是个小餐馆，但吃的东西还不错。