The term 'CURLER's surface' refers to the ICE surface used in the sport of curling. The crossword solution for this term is ICE, which is a three-letter word. ICE is an essential component of curling, as it provides a smooth, flat surface for the stones to slide across. The ICE must be maintained at a specific temperature and humidity level in order to ensure that the stones move properly. Additionally, the ICE must be regularly resurfaced in order to keep it in optimal condition.