The word "凛冽" is formed by combining the characters "凛" and "冽", both of which independently convey meanings related to coldness; "凛" suggests a severe, biting cold often with a stern quality, while "冽" refers to a piercing, frigid cold, particularly of air or water. Together, they create a compound word that intensifies the concept of extreme cold, typically used to describe harsh, freezing weather.