noun
An optical illusion caused by atmospheric conditions, especially the appearance of a sheet of water in a desert or on a hot road caused by the refraction of light from the sky by heated air.
The travelers were deceived by the mirage in the desert.
We thought we saw an oasis, but it was just a mirage.
Don't be fooled by that mirage, it's just a trick of the light.
His dreams of fame and fortune turned out to be nothing but a mirage.