a. incapable of being conceived or considered
a. 不能考虑的, 不能想像的, 想像不到的, 不合理的
1. It was unthinkable that she would fail the exam after studying so hard.
她努力学习后竟然会考试不及格，这真是不可想象。
2. The idea of losing such a close friend was unthinkable for him.
失去这样一个亲密朋友的想法对他来说是不可想象的。
3. For many people, the unthinkable happened when the city was hit by the storm.
对很多人来说，当城市遭遇风暴时，难以想象的事情发生了。