Frost/frɔːst/ Definition 1 of 5Pro Tip 1/3Weather Related Used to describe ice forming outside due to cold weather. Farmers worry about frost damaging crops. Pro Tip 2/3Visibility Hazard Frost can affect visibility by forming on windows, requiring scraping or defrosting. He used a scraper to remove the frost from his windshield. Pro Tip 3/3Not Snow Frost is not the same as snow; it forms directly on surfaces, not from falling precipitation. Frost decorated the leaves, but no snow had fallen.