flash in the pan

1. Someone or something that promises great success but soon fails: “The rock group that was all the rage last year turned out to be just another flash in the pan.”

Idioms and Phrases

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.

Example Sentences

Dubois, 27, becomes a top dog in the glamour division, but 'Dynamite' is not a flash in the pan and has long been prophesied for heavyweight stardom.

From BBC

“It’s just been an alignment of many things that has created this incredible moment for women’s sports that seems to be more than just a flash in the pan.”

From Seattle Times

So was the spring warmth just a flash in the pan?

From BBC

Of course, all this wouldn't be happening if the World Championship had been a flash in the pan.

From BBC

“While inflation was hotter than it’s been in a while, it may be more of a flash in the pan than the start of something worse,” said Brian Jacobsen, chief economist at Annex Wealth Management.

From Seattle Times