While this book does contain reference to other name origins (French, Norman, Latin, etc) this is in the section labelled “Irish First Names” – not a list of Irish origin names, but rather of first names used in Ireland. This does include names originating elsewhere, and it does note the frequency of use in Ireland for each including those names which have fallen out of fashion, sometimes a story about how the foreign name came into use there, are outdated, or names that are not actually names that had more interesting origins in fiction stories or epic poems and that people have decided to name their children after somewhere along the way.
There are other sections in the book that I find more personally helpful such as root words as well as a pronunciation guide. I do also appreciate along with the root words that the multiple modern Irish derivatives of the roots are noted.
Having spent a lot of time in research of Irish prehistory and mythology, I find the root word section helpful for fiction writing when I need to make up names from root words in the old way, combining nature elements to create a name, etc. I know they feel correct when I compare them with my research. The section for place names is also extremely useful for my own purposes.
I couldn’t say if the heraldry section is spot-on, but it does go so far as to note and cross-reference derivatives of family names, provides background including usually the oldest use of the family name and in most cases includes several well-known individuals with the family name for reference. An interesting read at any rate.
For strict linguistic research, I’m not certain if this book would be comprehensive enough, but for a fiction writer who needs to become a 48-hour expert in naming things the pre-Celtic way, there’s enough info in this book to point you in the right direction and use for continued reference. I bought my copy over 15 years ago and still use it today.
(Note: Originally published via Goodreads)