まやかし

noun, noun which may take the genitive case particle 'no'

deception; fake; sham

Refers to something that is not genuine, often with a nuance of trickery or illusion. Can be used as a noun or with の to modify another noun.

• 彼かれの話はなしはまやかしだった。

  His story was a deception.

• それはまやかしのダイヤモンドだ。

  That's a fake diamond.