senescence (noun) 

Senescence (suh-NEH-suhns) is the condition or process of deterioration with age. As I used it today: “In my experience, [businesses are like] organisms that grow in organic ways. In infancy and childhood, growth is fragile and must be both nurtured and protected. In adolescence, growth is rapid and must be guided and sometimes restrained. In maturity, growth slows and must again be stimulated to avoid senescence.”