sanctumEnglishOxford American Thesaurussanctum noun 1 the carving is done in that portion of the temple designed to be the sanctum: holy place, shrine, sanctuary, altar, inner sanctum, holy of holies; Latin sanctum sanctorum. 2 the inner bar remained a private sanctum for the regulars: refuge, retreat, bolthole, foxhole, hideout, hiding place, hideaway, study, den; Spanish querencia.