Answer: backslide

AnswerCrossword Clue
BACKSLIDERevert to old habits
BACKSLIDERelapse into bad habits
BACKSLIDERetrogress.
BACKSLIDEReverse progress
BACKSLIDEReturn to sinful ways
BACKSLIDEFall off the wagon
backslideRelapse into bad ways or error
backslideto fall back