The book Beyond Shannon and Sean: An Enlightened Guide to Irish Baby Naming states the name ÉTAÍN can be pronounced as either ay-teen or eden.
― Anonymous User 12/18/2009
3
In Old and Middle Irish a t, c, or p in other than initial position is normally pronounced as d, g, b respectively. Thus cét = 100 was pronounced ke:d & is now spelt céad from a Celtic word kentom which, you will note is very like the Latin word centum. So Étaín was pronounced /e:di:n/ & is written in modern Irish as Éadaoin or quite often in English dress as Aideen. Anyone who knows the modern Irish spelling system will see immediately that Éadaoin would be well represented by the English spelling Aideen. There is therefore no need to confuse it with the numeral 18 in English.