"Nine-day wonders" is a term used to describe something that creates a sudden sensation and then quickly fades. Synonyms for this phrase include "flash in the pan," "one-hit wonder," "fleeting phenomenon," "passing fancy," "ephemeral sensation," and "short-lived trend." Each of these phrases suggests something that is exciting and noteworthy for a brief period of time, but ultimately lacks staying power. Whether used to describe a pop culture fad or a momentary burst of public interest in a particular person or event, these synonyms capture the fleeting nature of passing trends and short-term sensations.