MIRAGE

noun Etymology: French, from mirer to look at, from Latin mirari Date: 1803 an optical effect that is sometimes seen at sea, in the desert, or over a hot pavement, that may have the appearance of a pool of water or a mirror in which distant objects are seen inverted, and that is caused by the bending or reflection of rays of light by a layer of heated air of varying density, something illusory and unattainable like a ~, see: delusion