fad

Etymology

Of English dialectal origin. Further origin obscure. Possibly from Old English ġefæd (“order, decorum”) (compare Old English ġefæd (“orderly, tidy”), fadian, ġefadian (“to set in order, arrange”), whence Middle English faden (“to arrange”)); or from French fadaise ("a trifling thought"; see fadaise).

noun

1. A phenomenon that becomes popular for a very short time.
   You're a fad, that means you're something that we've already had, but once you're gone, you don't come back. 2004, Andre R. Young, “Encore”, in Encore
   The pet rock fad was started by an advertising executive named Gary Dahl. The premise was simple: take ordinary rocks, glue eyes on them, and market them as pets. 2010, Eric J. Cesal, Down Detour Road: An Architect in Search of Practice, page 134