Sanatorium
SANATORIUM (a modern Latinism, formed from sanare, to cure, restore to health, sanus, whole, healthy, well; often wrongly spelled sanatorium or sanitarium), an establishment where persons suffering from disease, or convalescents, may be received for medical treatment, rest cures and the like; in recent modern usage particularly used for establishments where patients suffering from phthisis may undergo the open-air treatment (see THERAPEUTICS). The mis-spellings of the word, sanitarium and sanatarium, are due to a confusion of " sanatory," i.e. giving health, from sanare, and " sanitary," pertaining to health, from sanitas, health.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)