HUMIDIFIER

n. device which increases the amount of water vapor in the air of a room

A humidifier is a household appliance that increases humidity (moisture) in a single room or in the entire home. There are point of use humidifiers, which are commonly used to humidify a single room, and whole house or furnace humidifiers, which connect to a home's HVAC system to provide humidity to the entire house.
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Humidifier, n a device for adding moisture to dry air inside the home to help counteract the reduction in saliva that often occurs as a result of [more]Humidifier - Community and Resources

v. humidify, moisturize, dampen, moisten

A machine that puts moisture in the air.