noun
A medical facility for long-term treatment or convalescence, often for tuberculosis or chronic illness. Less common in modern Japanese than 療養所.
彼は結核の治療のため、山の中のサナトリウムに入った。
He entered a sanatorium in the mountains for tuberculosis treatment.
More common modern term for a sanatorium or convalescent hospital.
Loanword from English 'sanatorium', ultimately from Latin 'sanare' (to heal).