Regret Feel Unhappy Unable Feeling Sadness Sad Wrong

To feel sorry or unhappy about something you did or were unable to do. A feeling of sadness about something sad or wrong or about a mistake that you have made, and a wish that it could have been different and better.

She expressed (her) regret for calling me a liar.

It's never too late. Change it. You will not regret it. You'll be so happy you did it.

Don't say anything you might regret later.

It is better to look ahead and prepare than to look back and regret.