flash in the pan

noun

A transient occurrence with no long-term effect. / A career notable for early success not followed by significant accomplishment.

The success of his first book was just a flash in the pan.

意味（1）

A transient occurrence with no long-term effect.

The concept turned out to be merely a flash in the pan and is no longer used.

意味（2）

A career notable for early success not followed by significant accomplishment.

He was named best new director of 1940, but his career was a flash in the pan.