Ruing, which means to regret or feel sadness for something that has happened, has several synonyms that can be used interchangeably. These include lamenting, bemoaning, mourning, grieving, bewailing, and remorseful. When you feel ruing about a past action or event, you might lament the outcome or bemoan the lost opportunity. To express your feelings of regret more strongly, you might mourn or grieve a situation and lament the consequences of your actions. Additionally, you might express your remorseful or penitent feelings by bewailing the outcome or feeling despondent about what has happened. No matter which synonym you use, the ultimate meaning is the same: to feel regret or sadness about something that has occurred.