1. most covered with or affected by frost
Usage: superlative form of frosty
2. most unfriendly or hostile in manner
Usage: figurative use; superlative form of frosty

Examples

• The frostiest morning of winter left ice crystals on every surface.
• January had the frostiest temperatures we’d seen in years.
• She gave him the frostiest look when he arrived late.
• The reception was the frostiest he’d ever received from the committee.
• Even the frostiest critics praised her performance.
• The frostiest windows were impossible to see through.
• His frostiest response came when asked about the controversy.