The term 'prevailing custom' refers to the accepted norms of a particular society or culture. The crossword solutions for this term are 'MODE' (4 letters), 'RULE' (4 letters), and 'FASHION' (7 letters). MODE is a term used to describe the most popular way of doing something, while RULE is a set of regulations that must be followed. FASHION is a term used to describe the current trends in clothing, hairstyles, and other aspects of personal style. All three terms refer to the prevailing customs of a given society or culture.