Warman

To have previously been doing well at something and then form turns to shit.

There are two ways “Warman” can be used. For example - when playing golf. You are 2 over after 11 holes. Then lose 2 balls in the water and 4 putt. You would say “I’ve had a right Warman”

Or

when playing in a Fantasy Sports league, you have been doing really well. Then an opponent picks the same on form player as yourself and the player has a terrible game. For example you had Cancelo who had scored 10 points in the previous 3 games. A friend puts him in their team and Cancelo concedes 2 and gets sent off. You would say “I’ve been Warman’d”