desert cooler
n.— Note: Wikipedia has a decent entry for this type of air conditioner. Collins is the only mainstream dictionary publisher to include the term, but does so with an outdated definition: “a cooling device in which air is driven by an electric fan through wet grass.” «The South Korean white goods manufacturer is eying the lower-middle class consumer who largely continues to use water-based coolers, also known as desert coolers, to beat the summer heat.» —“It’s cool! LG plans ACs as cheap as coolers” in Seoul, South Korea LivePunjam June 4, 2009. (source: Double-Tongued Dictionary)