Source Information Heirlooms of Ireland [database on-line]. Provo, UT, USA: Operations Inc, 2006.
Original data: Osborne, Joseph F. Heirlooms of Ireland: An Easy Reference to Some Irish Surnames and Their Origins. Baltimore, MD, USA: Genealogical Publishing Co., 2002.

About Heirlooms of Ireland

This is a concise directory of Irish surnames. Arranged in tabular format, Heirlooms of Ireland provides the following information on some 2,500 Irish surnames: the surname and its variants, prefixes used with the name, the language from which the surname is derived, the century in which the surname can be traced in Ireland, the county or province in Ireland where the surname originated, a brief definition of the surname, the language from which the surname was derived, and pseudonyms for Irish surnames resulting from the British occupation of Ireland. Mr. Osborne has enhanced his book with contemporary and 16th-century maps of Ireland, a list of the present provinces and counties of Ireland, a brief introduction to Irish history, a listing of the Irish Clans of Old, a statistical breakdown on the most popular surnames in Ireland as of 1890, a description of the principal Irish Chieftains now and then, and a recommended reading list for further study.

In short, if you are in need of an easy-to-use directory of Irish surnames, look no further.