atavism, backset, backsliding, backward deviation, backward motion, backward step, check, comedown, descent, down, falling back, lapse, reaction, recession, recidivation, recidivism, recrudescence, recurrence, reentry, refluence, reflux, regress, regression, relapse, renewal, retroaction, retrocession, retroflexion, retrogradation, retrogression, retrusion, return, reversal, reverse, reverse of fortune, reversion, rollback, setback, severe check, sternway