an institution that treats chronic diseases, and provides supervised recuperation and convalescence
sana·to·rium sanatoriums or sanatoria in AM, also use sanitarium A sanatorium is an institution that provides medical treatment and rest, often in a healthy climate, for people who have been ill for a long time. sanatoria a type of hospital for sick people who are getting better after a long illness but still need rest and a lot of care
{i} rehabilitation center, hospital for the treatment of chronic diseases, convalescent center