Verbs

(v)fall backfall backwards and down
(v)lag, dawdle, fall back, fall behindhang (back) or fall (behind) in movement, progress, development, etc.
(v)fall backmove back and away from“The enemy fell back”
(v)fall back, resort, recurhave recourse to“The government resorted to rationing meat”
(v)relapse, lapse, recidivate, regress, retrogress, fall backgo back to bad behavior“Those who recidivate are often minor criminals”