fa·ta mor·ga·na 
(fä
′t
ə môr-gä
n
ə)
[Italian, mirage, Morgan le Fay (from the belief that the mirage was caused by her witchcraft) : fata, fairy (from Vulgar Latin *fāta, goddess of fate; see FAIRY) + Morgana, Morgan le Fay; akin to Medieval Latin Morgen (ultimately of Celtic origin ; perhaps akin to Old Irish Morrígan, a powerful, often sinister female supernatural being of Irish myth).]