improbable [ɪmˈprɒbəb(ə)l] неймовірний, неправдоподібний
It all sounded so improbable as he related his quest to Gwyneth.
Nor did it seem so improbable that he would.
She giggled, an improbable sound from a woman her size.
It was an improbable supposition, an impossible miracle, he knew.