If you say that something is unthinkable, you are emphasizing that it cannot possibly be accepted or imagined as a possibility.
例句
Her strong Catholic beliefs made abortion unthinkable.笃信天主教让她完全无法接受堕胎。
ADJ
匪夷所思的;难以想象的;不堪设想的
You can use unthinkable to describe a situation, event, or action which is extremely unpleasant to imagine or remember.
例句
This place is going to be unthinkable without you.没有了你,真不知道这地方会变成什么样子。...Monday's unthinkable tragedy.周一发生的难以置信的悲剧
英汉词典释义
adj.
不能考虑的, 不能接受的, 不可想像的, 难以置信的
It would be unthinkable to ask him to do that.叫他做那件事是毫无可能的。It is quite unthinkable that a child like him can speak a foreign language so fluently.像他这样的孩子居然能流利地说一种外语, 真是令人难以置信。