- sanctum (n.)
- 1570s, from Latin sanctum "a holy place," as in Late Latin sanctum sanctorum "holy of holies" (from Greek to hagion ton hagion, from Hebrew qodesh haqqodashim), from neuter of sanctus "holy" (see saint). In English, sanctum sanctorum attested from c.1400; sense of "a person's private retreat" is from 1706.