(n.) The act of passing back or returning; retrogression; retrogradation.

Brownian movement Freudian fixation about-face advance angular motion arrested development ascending ascent atavism axial motion backflowing backing backset backsliding backward deviation backward motion career climbing comedown course current debasement decadence decadency declension declination decline deformation degeneracy degenerateness degeneration degradation demotion depravation depravedness depreciation derogation descending descent deterioration devolution disenchantment downtrend downturn downward mobility downward motion downward trend drift driftage drop dying ebb ebbing effeteness fading failing failure failure of nerve fall falling back falling-off father fixation fixation flight flip-flop flow flux forward motion infantile fixation involution lapse libido fixation loss of tone mother fixation mounting oblique motion ongoing onrush parent fixation passage plunging pregenital fixation progress radial motion random motion recidivation recidivism reclamation reconversion recrudescence recurrence reflowing refluence reflux regress rehabilitation reinstatement relapse renewal restitution restoration retreat to immaturity retrocession retrogradation retrogression retroversion return returning reversal reverse reversion reverting revulsion rising run rush set setback sideward motion sinking slippage slipping back slump soaring sternway stream subsiding throwback traject trajet trend turn turnabout upward motion wane