inconceivable
US
UK inconceivable adj: (impossible to imagine)
SC 不可思议的 bù kě sī yì de
SC 无法相信的 bù kě sī yì de ，wú fǎ xiāng xìn de
Traveling at the speed of light is inconceivable.
it's inconceivable: informal (it's unthinkable or impossible) (非正式用语)
SC 这是不可想象的 zhè shì bù kě xiǎng xiàng de
It's inconceivable that he will fail his exams after all the work he's done.