Condensed water vapor in cloudlike masses lying close to the ground and limiting visibility. An obscuring haze, as of atmospheric dust or smoke. A mist or film clouding a surface, as of a window, lens, or mirror. A cloud of vaporized liquid, especially a chemical spray used in fighting fires. A state of mental vagueness or bewilderment. Something that obscures or conceals; a haze: shrouded their actions in a fog of disinformation. A blur on a developed photographic image. To cover or envelop with or as if with fog. To cause to be obscured; cloud. To make vague, hazy, or confused: a memory that had been fogged by time. To obscure or dim (a photographic image). To be covered with or as if with fog. To be blurred, clouded, or obscured: My glasses fogged in the warm air. To be dimmed or obscured. Used of a photographic image. A new growth of grass appearing on a field that has been mowed or grazed. Tall, decaying grass left standing after the cutting or grazing season.