It's highly improbable that aliens abducted you.
The idea that the sun spins around the Earth is an example of something that would be described as a improbable idea.
When they are calling for a 90 percent chance of rain, this is an example of a time when sunshine is improbable.
Due to the loss of power, it is improbable that we will begin on time.
Origin of improbable
- From Middle French improbable, from im- + probable