decay
Definitions
The process or result of rotting or decomposing through the action of bacteria and fungi.
A gradual decline in quality, power, or vigor; deterioration.
The process by which a radioactive substance loses energy by radiation.
Examples
The old wooden fence began to decay after years of exposure to the rain.
Urban decay has become a significant issue in many neglected city centers.
The scientist studied the rate of radioactive decay in the mineral sample.