n. The aggregation of a vast number of minute globules of water in the air near the earth's surface, usually produced by the cooling of the air below the dew-point, whereby a portion of its vapor is condensed.n. Hence A state of mental obscurity or confusion: as, to be in a fog of doubt.n. In photography, a uniform coating covering a developed plate, more or less destructive to the picture in proportion to its opacity. It results from chemical impurities, from exposure of the sensitized film to light, from errors in manipulation, etc.To envelop with or as with fog; shroud in mist or gloom; obscure; befog.To cloud or coat with a uniform coating or discoloration, as in photography: as, an over-alkaline developer will fog the plate. see fog, n., 3.To become covered or filled with fog.In photography, to become clouded or coated with a uniform coating or discoloration: said of a negative in course of development. See fog, n., 3.n. Aftergrass; a second growth of grass; aftermath; also, long grass that remains on land through the winter; foggage.n. Moss.To feed off the fog or pasture in winter: as, to fog cattle.To eat off the fog from: as, to fog a field.To become covered with fog or moss.To seek gain by base or servile practices (whence pettifogger).Gross; fat; clumsy.n. An atmospheric haze due to the presence of fine solid matter, such as dust or fine soot from soft coal fires or ashes from forest and prairie fires. These carbon particles collect about themselves special atmospheres of aqueous vapor and other gases. The spectrum of the transmitted light shows only the red and ultra-red waves. As the upper layers of the dry fog cool off by radiation and the little atmospheres of vapor become water, the dry fog changes to a drizzling mist and often to steady rain. Prairie fires and the resultant dry fog are mentioned by Marco Polo in his travels in India.