mi·rage 
(mĭ-räzh)
(mĭ-räzh)n.
1. An optical phenomenon that creates the illusion of water, often with inverted reflections of distant objects, and results from distortion of light by alternate layers of hot and cool air. Also called fata morgana.
2. Something illusory or insubstantial.
[French, from mirer, to look at, from Latin mīrārī, to wonder at, from mīrus, wonderful; see smei- in the Appendix of Indo-European roots.]
mirage