flash in the pan

Someone or something whose success or popularity is short-lived. With only one hit song, it was obvious that the young pop star was going to be just another flash in the pan. The new startup created a lot of buzz, but it ended up being just another flash in the pan, out of business after just two years.

Fig. someone or something that draws a lot of attention for a very brief time. I'm afraid that my success as a painter was just a flash in the pan. Tom had hoped to be a major film star, but his career was only a flash in the pan.

An effort or person that promises great success but fails. For example, His second novel proved to be a flash in the pan, or We had high hopes for the new director, but she was a flash in the pan. This metaphoric term alludes to the 17th-century flintlock musket, which could be fired only when the flash of the priming powder in the lockpan ignited the charge in the bore. When it failed to ignite, there was only a flash in the pan and the gun did not shoot.

One that promises great success but fails.

An ultimate disappointment after a promising start. Flintlock muskets and pistols had a priming pan that was filled with a small quality of gunpowder. When the trigger was pulled, the flint struck a piece of steel to create a spark that ignited the powder, which in turn set off the main gunpowder charge to launch the musket ball. Whenever the flint-and-steel spark failed to light the main charge, there was a flash in the pan, but no shot. And that was the disappointment after a potentially useful beginning.