But all that came to mind was a preposterous notion that someone had called his name.

Even if he does believe in the most preposterous notions.

Ann was just trying to fill our heads with her preposterous notions.

This seemed on the face of it such a preposterous notion that Arthur practically choked.

What a preposterous notion to get into your head!

At first sight, I agree that sounds like a preposterous notion.

Really, if such a preposterous notion could ever make sense Everything fitted.

But I cannot agree to such a preposterous notion as your going to live with your lover.

She had no argument for such a preposterous notion.

How could we possibly approach our colleagues with such preposterous notions of alien intervention?