"Nineday wonders" is a phrase used to describe something that is short-lived or fleeting. Synonyms for this phrase include "flash in the pan," "one-hit wonder," "fleeting phenomenon," "flashy spectacle," "temporary sensation" and "transient attraction." These words can be used to describe anything from a viral video or a trend that quickly fizzles out, to a celebrity or musician who enjoys a brief period of fame. Additionally, "passing fancy" and "ephemeral craze" are two more synonyms that can be used to convey the idea of something that is here today and gone tomorrow.