A wasting away, especially of body tissue, an organ, etc., or the failure of an organ or part to grow or develop, as a result of insufficient nutrition or a disease: "Many people suffer from atrophies of tissues, bodily organs, or the entire body because of a reduction in the sizes or numbers of their cells."

"Atrophy is commonly caused by the lack of use; such as when a limb (arm, hand, etc.) has been immobilized in a plaster cast or by inadequate cell nutrition because of poor blood circulation."

"Physicians are aware that atrophy may also take place during a prolonged serious illness, when the body needs to use up the protein reserves in the muscles."

1. To waste away as a result of the degeneration of body cells: "Without adequate exercise, the muscles will atrophy regardless of one's age."

"The man significantly atrophied during his bedridden illness."

"Many elderly people have "sarcopenia" or atrophying of the muscles because either they don't exercise at all or not adequately. We are never too old to exercise!"

2. The degeneration, decline, or decrease, because of the lack of using something: "The professor argued that there was a progressive atrophy of freedom and independence of thought because too many people were simply ignoring their political rights."