The term SUFFIX FOR LUNCHEON can be completed with the 4-letter word ETTE. This suffix is derived from French and is used to denote a feminine form of a noun, such as in the words 'WAITRESS' or 'PRINCESS.' It is often used to refer to a small version of something, such as a 'kitchenette' or a 'CIGARETTE.' In this case, it is used to refer to a smaller version of a luncheon, which is a light meal typically eaten in the middle of the day.