Halidom is an obscure, now obsolete English word meaning something considered holy or a sanctuary. Some accounts also list it as meaning 'holy doom', doomsday. Thus, the Keeper of Halidom would refer to someone who protected a sanctuary. This would imply the Keeper of Halidom is the protector of The Sanctuary of Zi'Tah and/or the nearby Cermet Headstone. An alternate rendering would be as the keeper of doomsday, or known as the Keeper of the Apocalypse (a title used in Chains of Promathia to refer to the avatar of Emptiness, the reincarnation of Promathia). However in older English, doomsday (or 'domesday') simply refers to a day of judgment (Hence the Domesday Book, the first census of England undertook by William I) and has no literal connotations to the Apocalypse.
- The word is unequivocally derived from the Germanic "Heiligtum" meaning something holy, hence roughly "Sanctuary". To connect it with "Doom" is folk etymology, and far off the mark.