The quality or state of being chilly; moderate coldness or a sense of unfriendliness or coldness in behavior or attitude.
Chilly (from Middle English chil, to be cold) + -ness (suffix making abstract nouns); '-ness' attaches to adjectives to create the noun form of their quality.
The beauty of 'chilliness' is that it means both physical coldness AND the cold, unfriendly feeling you get from someone—English efficiently uses the same word for both the temperature and the vibe.
Complete word intelligence in one call. Free tier — 50 lookups/day.