|1.||foul weather fan|
A sports fan who only supports his team when they struggle. They routinely root for the under dog.
It can also be applied to fans of other things, in particualar indie music. When a band makes it big, their foul weather fans will write them off as "sellouts."
Opposite of fair-weather fan, one who only supports a sports team when they do well.
Bob only liked the Giants until they won 88 games in 2009. Now that they won the 2010 World Series, he won't go to games any more. What a foul weather fan.
Jay only liked Indie Snob Band #675 until they made it big with their hit "Two Chords" which succeeded to to the lack of Dave Navarro and his 2 chords of bland on the airwaves.