'atrophy' definitions:

Definition of 'atrophy'

From: WordNet
noun
A decrease in size of an organ caused by disease or disuse [syn: atrophy, wasting, wasting away]
noun
Any weakening or degeneration (especially through lack of use) [syn: atrophy, withering]
verb
Undergo atrophy; "Muscles that are not used will atrophy"

Synonyms of 'atrophy'

From: Moby Thesaurus