unspeakable

adj.不能以言语表达的；坏透了的

There is something unspeakable in these outposts. 边缘的有些地方难以名状。

The unspeakable odour clung to the room. 一股难以形容的气味充斥着房间散不出去。

America's invasion of the country must be done for unspeakable political purpose. 美国入侵这个国家一定是出于不可告人的政治目的。