fad

fad
/fæd; fæd/ n
fashion, interest, preference, enthusiasm, etc that is not likely to last 流行的时尚、 爱好、 狂热等
    Will Tom continue to collect stamps or is it only a passing fad? 汤姆还在集邮呢, 还是热劲已过?

牛津英汉双解词典