early 15c., "too large to be conceived, unimaginable," from un- (1) "not" + think (v.) + -able. Meaning "incapable of being framed by thought" is recorded from mid-15c.
雙語例句
1. Edward VIII had done the unthinkable and abdicated the throne.
愛德華八世竟主動遜位，真是匪夷所思。
來自柯林斯例句
2. Any thought of splitting up the company was unthinkable they said.
他們說，任何將公司拆分開的想法都是不能接受的。
來自柯林斯例句
3. Her strong Catholic beliefs made abortion unthinkable.