The term regress refers to a move or step backward, often in reference to a previous state or condition. It can also mean a regression towards an earlier stage of development or behavior, as if one is reverting to an older way of thinking or acting. In psychology, it may refer to the return of symptoms or behaviors that were previously overcome through therapy or treatment. Additionally, regress can describe a decrease in size, amount, strength, or quality after reaching its peak or highest point.