The term ICE UP can be solved in three different ways in a crossword puzzle. The first solution is FREEZE, which is a 6-letter word meaning to lower the temperature of something to the point where it becomes solid. The second solution is FROSTOVER, which is a 9-letter word meaning to cover something with a layer of frost. The third solution is FREEZEOVER, which is a 10-letter word meaning to cause something to become completely frozen.