To revert to a previous, less advanced state or condition, especially in terms of behavior or beliefs. After months of progress, he began to backslide into his old habits.
To lapse morally or spiritually; to relapse into sin, error, or wrongdoing, especially after a period of improvement or commitment. Some believers feared they would backslide if they stopped attending weekly services.
To slide backwards physically or downhill, often unintentionally. The car backslid several feet before the driver regained control.