The term 'SIDE OF A DINER' can be solved by two crossword solutions: MASHED (6 letters) and SLAW (4 letters). Mashed is a dish made of potatoes that have been boiled, peeled, and mashed with butter, milk, and salt. It is often served as a side dish in diners. Slaw is a salad made of shredded cabbage and other vegetables, usually dressed with mayonnaise or a vinaigrette. It is also a popular side dish in diners.