This is a linguistic database of Irish-language surnames. The database provides in-depth lexical and grammatical information regarding a selection of high-frequency surnames of Irish-language origin. Irish-language surnames in the database are arranged in clusters which contain their synonyms in Irish and their equivalents in English. Inflected forms of the Irish-language surnames are also given. The database currently comprises over 1,000 surname clusters. Population of the database was data-driven, and each cluster represents a surname of Irish-language origin that was registered four times or more to babies born in Ireland between 2016–20. We hope to continue expanding the scope of the database. Surname frequency data is provided by the Central Statistics Office (CSO).

The database can be searched. Search results include exact matches (i.e. links to clusters where one of the surnames matches your query exactly), related/similar matches (i.e. links to clusters where one of the surnames matches your query after it has been query-expanded by the Irish Surname Index), and spelling suggestions (i.e. surnames that are similar to your query as computed by the Levenshtein edit-distance algorithm). You can click a related/similar surname or a spelling suggestion to search again, or click one of the cluster links to display that cluster.

The database can be browsed alphabetically using four different sorting keys.

The database is aimed at users who wish to either map a surname to its conventional/usual equivalent in the other language, or standardise a surname within the same language. We also aim to help users, both human and machine, to use and recognise Irish surnames in text and in speech in a way that is grammatically correct.

The database does not provide a comprehensive set of variant forms, provides only limited etymological information, and does not give information on the genealogical or geographic origins of Irish surnames. For this, see the The Oxford Dictionary of Family Names of Ireland by Dr Kay Muhr and Dr Liam Ó hAisibéil published by Oxford University Press.

The dataset and the expansion algorithm used to generate the inflected forms is available to download here. The structure and design principles of the database are described in this publication:

Brian Ó Raghallaigh, Michal Boleslav Měchura, Aengus Ó Fionnagáin & Sophie Osborne. 2021. Developing the Gaois Linguistic Database of Irish-language Surnames. Names, 69(1), 10–19. https://doi.org/10.5195/names.2021.2251

Version 1.0 of the database was published on 08/04/2020. This version comprised 664 clusters and was based on statistics from the year 2017. Version 2.0 of the database was published on 26/03/2022. This version comprised 1,049 clusters and was based on statistics from the years 2016–20. Muhr & Ó hAisibéil (2021) was consulted for the clusters added in Version 2.0. Mag- surnames are included in Version 2.0. Justin Ó Gliasáin was postdoctoral researcher on Version 2.0.

• MacLysaght, Edward. 2013. The Surnames of Ireland. 6th ed. Dublin: Irish Academic Press.
• Muhr, Kay & Liam Ó hAisibéil. 2021. The Oxford Dictionary of Family Names of Ireland. Oxford: Oxford University Press.
• Ó Corráin, Donnchadh & Fidelma Maguire. 1990. Irish Names. 2nd ed. Dublin: The Lilliput Press.
• Ó Droighneáin, Muiris. 2013. An Sloinnteoir Gaeilge agus an tAinmneoir. 12th ed. Dublin: Coiscéim.