1. an optical illusion in which atmospheric refraction by a layer of hot air distorts or inverts reflections of distant objects

2. something illusory and unattainable

1.海市蜃楼;幻境
Amirage is something which you see when it is extremely hot, for example in the desert, and which appears to be quite near but is actually a long way away or does not really exist.

e.g. Through my half-closed eyelids I began to see mirages...
透过我半睁半闭的双眼，我看到了海市蜃楼。
e.g. It hovered before his eyes like themirage of an oasis.
它在他眼前晃动，好像海市蜃楼里的绿洲。

2.妄想;幻想
If you describe something as amirage, you mean that it is not real or true, although it may seem to be.

e.g. The girl was amirage, cast up by his troubled mind...
那个女孩是他的幻觉，是他那忧郁不安的头脑妄想出来的。
e.g. The objectivity of science is amirage.
所谓科学的客观性是一种幻想。