1. impossible to imagine or believe; unthinkable
Usage: less common variant of ‘inconceivable’

Examples

• It was unconceivable that such a tragedy could happen in their quiet town.
• The amount of data processed by modern computers would be unconceivable to earlier generations.
• She found it unconceivable that her best friend would betray her trust.
• The scale of the universe is unconceivable to the human mind.
• It seemed unconceivable that he could finish the project in just one day.
• The poverty in some regions is unconceivable to those living in wealthy nations.