(n.) The process of growing worse, or the state of having grown worse.

about-face accommodation adaptation adjustment aggravation alteration amelioration amplification annoyance apostasy atrophy augmentation betterment break change change of heart changeableness comedown constructive change contentiousness continuity conversion crumbling debasement decadence decadency decay decaying declension declination decline decomposition deepening defection deformation degeneracy degenerateness degeneration degenerative change degradation deliberate aggravation demotion depravation depravedness depreciation derogation descent devaluation deviation devolution difference discontinuity disintegration dislocation disruption dissolution divergence diversification diversion diversity downfall downgrade downtrend downturn downward mobility downward trend drop dry rot dying ebb ebbing effeteness embittering embitterment enhancement enlargement exacerbation exasperation fading failing failure failure of nerve fall falling-off fitting flip-flop gradual change heightening impairment improvement increase intensification involution irritation lapse lessening loss of tone magnification melioration mitigation modification modulation overthrow provocation qualification radical change re-creation realignment redesign reform reformation regression remaking renewal reshaping restructuring retrocession retrogradation retrogression reversal revival revivification revolution rotting ruin sharpening shift slippage slump souring spoiling sudden change switch total change transition turn turnabout upheaval variation variety violent change wane waning worsening