osteoporosis
noun(also brittle bone disease)
[uncountable] (a condition in which the bones become weak and are easily broken, usually when people get older or because they do not eat enough of certain substances 骨质疏松；骨质疏松症 Oxford Collocations DictionaryOsteoporosis is used before these nouns:- prevention
Word Originmid 19th cent.: from osteo- ‘bone’ + Greek poros ‘passage, pore’ + -osis.