1. A suspension in the air consisting of an aggregate of microscopic water droplets or wet hygroscopic particles (of diameter not less than 0. 5 mm or 0. 02 in. ), reducing the visibility at the earth's surface to not less than 1 km or 5/8 mi. The term mist is used in weather reports when there is such obscurity and the associated visibility is 1000 m or more, and the corresponding relative humidity is 95% or more, but is generally lower than 100%. These hydrometeors form a thin greyish veil that covers the landscape. It also reduces visibility, but to a lesser extent than fog. 2. In popular usage in the United States, same as drizzle.