warn somebody off

He could have warned her off, but what would be the point?

But a small voice in the back of his head warned him off.

Of course he's going to try and warn us off.

Why do you think I tried to warn her off?

Her mother may have warned him off but that didn't mean he had to go!

The outside of the house is quite enough to warn them off.

The one you're using ought to have warned me off.

Some people we can warn off easily, but not you.

Your program saw a possible problem and warned me off, saving my data by not running.

"It does when the woman you're involved with is a major player in a case you've been warned off."