Related Clues:

• It's temporarily in
• Mode of the moment
• Wacky WallWalker, for one
• Pokémon, for one
• Pet Rock, famously
• Passing thing
• Insanity
• Passing fancy
• The Macarena, e.g.
• It surrounded 18-Down in 1996
• Suffix with Wrestle
• Passing rage
• What the Beatles inspired
• The Beatles, once
• It's in for a while