(n.) The act of slipping; also, the amount of slipping.

avalanche coast comedown debasement decadence decadency declension declination decline deformation degeneracy degenerateness degeneration degradation demotion depravation depravedness depreciation derogation descent deterioration devolution downtrend downturn downward mobility downward trend drop dying ebb effeteness fading failing failure failure of nerve fall falling-off glide glissade glissando involution landslide landslip lapse loss of tone regression retrocession retrogradation retrogression sideslip skid slide slip slither slump snowslide snowslip subsidence wane