humidify
Concise Oxford English Dictionary © 2008 Oxford University Press:
humidify/hjʊˈmɪdɪfʌɪ/
▶verb (humidifies, humidifying, humidified) (often as adj. humidified) increase the level of moisture in (air).
– derivatives
humidification noun,
humidifier noun.
humidification noun,
humidifier noun.
'humidify' also found in these Oxford entries:

