sarcopeniaPronunciation: /ˌsɑːkəʊˈpiːnɪə/Definition of sarcopenia noun [mass noun] Medicine the loss of skeletal muscle mass and strength as a result of ageing. Origin: 1990s: from Greek sarx, sark- 'flesh' + penia 'poverty'sarcopenia in other Oxford dictionaries Definition of sarcopenia in the US English dictionary