“What? Don't be ridiculous!”

You were at a restaurant with your daughter and there was a really attractive woman sitting nearby. You noticed her and looked at her a few times while you were there. After you leave the restaurant, your daughter teased you for checking out the woman. You don't want to admit that you were looking at her, so you say:

What? Don't be ridiculous!

What?

You say "What?" when you can't hear or understand what someone says. But you can also say "What?" when they say something surprising:

A: I've decided that I'm dropping out of school.

B: What? Are you serious?

Don't be ridiculous!

In casual situations, you say "Don't be ridiculous!" when someone says something that's totally wrong. It means "that's not true!" It's especially used when someone says something untrue about you or accuses you of doing something wrong. For example, you can use this phrase when:

• You left out the leftovers from dinner for an hour after you ate, and your wife is worried that they're not safe to eat now. You think it's perfectly safe.
• Your son is worried that he might not be able to get into the university he applied for. He says that there's no way he'll get in. You want to cheer him up.

The word "ridiculous" means "funny" in a way that's totally impossible and unbelievable.