osteopeniaPronunciation: /ˌɒstɪəʊˈpiːnɪə/Definition of osteopenia noun [mass noun] a medical condition in which the protein and mineral content of bone tissue is reduced, but less severely than in osteoporosis. Origin: 1960s: from osteo- and Greek penia 'poverty'osteopenia in other Oxford dictionaries Definition of osteopenia in the US English dictionary