When someone lapses back, it means they have returned to a previous state or behavior. Some synonyms for lapse back might include relapse, regress, or retrogress. These all imply a return to a less desirable condition that had been overcome or left behind. Another possible synonym is backtrack, which suggests going back on progress made or retracing steps. Other related words might include revert, recidivate, or fall back. All of these have a negative connotation, indicating a failure to maintain progress or improvement. To avoid lapsing back into old habits or patterns, it's important to stay mindful and continue making conscious efforts to move forward in a positive direction.