chilly

The word 'chilly' is a straightforward formation from the noun 'chill', which itself has deep Germanic roots related to coldness and frost. The addition of the productive adjectival suffix '-y' directly transforms the concept of cold into a descriptive quality. This process illustrates a common pattern in English where a concrete noun (chill) gains an abstract, qualitative sense (chilly) through suffixation. The modern meanings retain this core link to coldness, extending it literally to temperature and metaphorically to unfriendly, emotionally cold behavior.

Structure: chill (cold) + y (adjective suffix) "chill" originates from Old English ciele (cold, frost), from Proto-Germanic kaliz. The suffix "-y" is from Old English -ig, a common adjective-forming suffix.