The word "dew" refers to small drops of water formed from moisture condensation in the atmosphere. The temperature at which the water vapor becomes a liquid at the same rate as it evaporates at a given atmospheric pressure is referred to as a "dew point."
When a temperature is above the dew point, the formation of liquid outpaces the evaporation of liquid, leading to greater dew formation. The reverse occurs when the temperature is below the dew point. The dew point temperature is related to humidity measurements. "Dew" may also refer to beads of perspiration that form on animals in high temperatures to cool themselves off.