fad
n. an abrupt but short-lived change in the opinions, behaviors, or lifestyles of a large number of widely dispersed individuals. Preoccupations with new products, dances, television programs, and fashions can be considered fads when many people quickly embrace the trend but then lose interest just as rapidly. Fads often pertain to relatively trivial matters and thus disappear without leaving any lasting impact on society. Extremely irrational, expensive, or widespread fads are termed crazes.