Evanescent is an adjective that means vanishing like vapor.

Our word of the day is derived from the Latin word evanescent (ay ven uh SHENT) which means ‘to disappear.’ Evanescent may be used to refer to something that disappears in a literal sense or it can be used more figuratively as a synonym of ‘ephemeral’ or ‘temporary.’ For example: That recollection of our family singing around the fireplace at Christmas will stay with me forever. The moment itself may have been evanescent, but the memory is eternal.