Icy describes something extremely cold, covered with ice, or having the dangerous slipperiness that ice creates. When sidewalks become icy after a winter storm, you have to walk carefully to avoid slipping. An icy wind cuts through your jacket and makes you shiver. A glass of icy water might be so cold it makes your teeth hurt.

The word also describes a person's cold, unfriendly behavior. When someone gives you an icy stare, their expression is so cold and unwelcoming that it feels like being hit with a blast of Arctic air. An icy tone of voice sounds sharp and hostile, warning you that the person is angry or disapproving. If your friend responds to your apology with icy silence, that frosty reception tells you they're not ready to forgive yet.

This emotional meaning works because ice itself is hard, sharp, and unwelcoming. Just as actual ice can be dangerous and unpleasant, an icy attitude creates distance between people and makes social situations uncomfortable. When someone thaws from their icy mood, they become warmer and more approachable again.