一时的兴趣（或爱好）
something that you like very much for a short period
But for me, parachuting was no passing fancy. 但是对我来说，跳伞可不是一时的兴趣。
Musical comedies are popular at the moment, but it could be a passing fancy.
His desire to run for president was no passing fancy.
It is obvious that streaming shows online is more than a passing fancy.
Although she was in love with Alejandro, to him she was no more than a passing fancy.
See also: fancy noun (THING/PERSON YOU LIKE)