deterioration
de.te.ri.o.ra.tion \di-.tir-e--*-'ra--sh*n\ n : the action or process of deteriorating : the state of having deteriora ted mean the falling from a higher to a lower level in quality, character, or vitality, DETERIORATION implies impairment of vigor, resilience, or usefulness; DEGENERATION stresses physical, intellectual, or esp. moral retrogression; DECADENCE presupposes a reaching and passing the peak of development and implies a turn downward with a consequent loss in vitality or energy; DECLINE differs from DECADENCE in suggesting a more markedly downward direction and greater momentum, more obvious evidence of deterioration, and less likelihood of a return to earlier vigor or state of excellence SYN syn DETERIORATION, DEGENERATION, DECADENCE, DECLINE
Webster's English Dictionary