atrophy
Definitions
The wasting away or decrease in size of an organ or tissue, typically due to disease, degeneration, or lack of use.
A progressive decline in effectiveness or vigor due to underuse or neglect.
Examples
Without regular exercise, the muscles in his leg began to atrophy during his long recovery.
The once-thriving local economy began to atrophy as the main factory closed its doors.
Prolonged inactivity can cause the brain's cognitive functions to atrophy over time.