sanatorium
Concise Oxford English Dictionary © 2008 Oxford University Press:
sanatorium /ˌsanəˈtɔːrɪəm/
▶noun (pl. sanatoriums or sanatoria /-rɪə/) an establishment for the treatment of people who are convalescing or have a chronic illness.
■ Brit. a place in a boarding school for sick children.
– origin C19: mod. L., based on L. sanare ‘heal’.
'sanatorium' also found in these Oxford entries:

