os ‧ te ‧ o ‧ po ‧ ro ‧ sis /ˌɒstiəʊpəˈrəʊsəs, ˌɒstiəʊpəˈrəʊsɪs $ ˌɑːstioʊpəˈroʊ-/ BrE AmE noun [uncountable]
[ Date: 1800-1900 ; Origin: osteo- + Modern Latin porosis (from Latin porus ; ⇨ ↑ pore 1 ) ]
a medical condition in which your bones become weak and break easily:
the risk of developing osteoporosis