Originally originating from the game Wide World (where when a 6 is rolled
the players are moved on the weather vane
across the board, invariably where they do not want to go), weathervaned means to be generally beaten, owned or pwned, often unexpectedly.
1
Jeff: I'm only one
square away from winning
Andrew: (Rolling a 6) WEATHERVANED!!!!
2
Reginald: Hullo, may I join you in partaking in this game of
basketball.
Jamaal: No. (Hurling ball in Reginald's face) WEATHERVANED!!!!!!11!one!