'adytum' originates from Latin, specifically the word 'adytum', where 'a-' meant 'not' and 'dyton' meant 'to enter'.

'adytum' changed from the Greek word 'ἄδυτον' (aduton) and eventually became the modern English word 'adytum'.

Initially, it meant 'a place not to be entered', but over time it evolved into its current meaning of 'a sacred place that is not accessible to the public'.