fad
n. countable B2 Upper Intermediate US //ˈfæd// UK //fˈæd// fad
n. something that is very popular for a short time and then quickly forgotten. It is often a style, activity, or interest that people follow with great excitement.
n. an intense and widely shared enthusiasm for something, especially one that is short-lived and without basis in the object's intrinsic value.
That new dance style is just a passing fad.
Many people thought that social media would be a temporary fad, but it has completely changed how we communicate.
The history of fashion is littered with fads that seemed essential at the time but now appear bizarre or even comical to modern observers.
Usage
Often modified by adjectives like 'passing', 'latest', or 'short-lived'.