Slippage :  (noun)
1: a decrease of transmitted power in a mechanical system caused by slipping
2: decline from a standard level of performance or achievement
3: failing to hold or slipping out of place; "the knots allowed no slippage"

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,