What's the "een" in Halloween?
1839, Modern Latin, noun use of neuter of Late Latin adjective sanitorius "health-giving," from Latin sanat-, past participle stem of sanare "to heal," from sanus "well, healthy, sane" (see sane). Latin sanare is the source of Italian sanare, Spanish sanar.
sanatorium san·a·to·ri·um (sān'ə-tôr'ē-əm) or san·a·tar·i·um (-târ'ē-əm)
n. pl. san·a·to·ri·ums or san·a·to·ri·a (-tôr'ē-ə) or san·a·tar·i·ums or san·a·tar·i·a (-târ'ē-ə)
An institution for the treatment of chronic diseases or for medically supervised recuperation.
A resort for improvement or maintenance of health, especially for convalescents. Also called sanitarium.