I can't stand golf, but I've always loved this term since I learned it from a golf-playing friend. From the Golf Rules dictionary:
Any temporary accumulation of water on the course (other than a water hazard) visible before or after the player takes his stance. It includes:
-snow and ice
-overflow from a water hazard if outside the hazard
-a pitch mark filled with water
It does not include:
-soft mushy ground
-water which appears when pressing a footmark down -dew and frost
-water on the putting green which was not visible when taking stance but which became visible when approaching the ball.
The player is entitled to relief when his ball lies in or touches casual water or when it is on the course and interferes with his stance or area of intended swing (or if the ball is on the putting green, his line of putt).