Explain it in plain words.

I prefer plain knitting when I make sweaters.

The Olympic Games originated in Olympia, a plain in the western part of the Peloponnese peninsula in Greece.

The plainness of her words made it clear that she was not happy.

The Great Plains stretch across the grasslands between the Rocky Mountains and the Mississippi River.

I prefer plain chocolate without any added sugar.

Plain dealing is essential in business transactions.

You can use plain flour instead of self-raising flour.

The project has been plain sailing so far.

Plains Indian tribes relied on buffalo for their survival.