The term SUB STORE can be broken down into two words: DELI (4 letters) and SUB (3 letters). A deli is a type of store that specializes in selling prepared foods such as sandwiches, salads, and other cold cuts. A SUB is a type of sandwich that is usually made with a long roll filled with various meats, cheeses, and vegetables. Therefore, a SUB STORE is a store that specializes in selling subs and other deli items.