The term 'Winter Hat Extension' is a crossword solution that consists of two words: 'Earflap' and '7 letters'. Earflaps are pieces of fabric or fur that hang down from the sides of a hat, usually to provide extra warmth and protection from the cold. They are commonly found on winter hats, such as beanies, trappers, and aviators. The term '7 letters' refers to the length of the word 'earflap', which has seven letters.