white elephant
無用的負擔或裝飾品
口語·指昂貴而無用的東西
英文釋義
an expensive or burdensome possession or project that is more trouble than it is worth
例句
That old mansion is a white elephant; it costs a fortune to maintain and nobody uses it.
典故來源
源自古代暹羅（今泰國）國王將白象賜予臣下的習俗，因白象被視為神圣但飼養昂貴，成為負擔。