unthinkable
/ʌnˈθɪŋkəbəl/
adjective
- Impossible to imagine or accept as possible; extremely shocking or surprising.
- It was unthinkable that the team would lose after such a strong start.
- The idea of betraying her best friend was unthinkable to her.
- In the 1800s, traveling to the moon was unthinkable.
Antonyms