Patronyms and Other Additives
Many Irish surnames are concentrated in particular parts of the country and there are areas where a single surname may account for a large proportion of the population. Examples include O'Reilly in County Cavan, Ryan in County Tipperary and East County Limerick, or O'Sullivan in the Beara peninsula of West Cork; or areas, such as Glenullin in the Sperrins, where there are several dominant surnames (in that instance O'Kane, Mullan, McNicholl and some others). In such cases, the surname may also acquire an additive in popular usage to differentiate one group bearing the same surname from another.
This sometimes originates as a simple patronym - that is, a James whose father was Harry might be referred to as Harry's James - but may be passed to later generations, so that James' son Pat might be Harry's Pat. This can also occur if a person becomes well known by a nickname: his children may take his nickname as an additive. For example, if Seán O'Brien was often referred to as "Badger", his son Patrick might referred to orally as Pat Badger and written as Patrick O'Brien (B).
In Tipperary, additives are particularly common among those bearing the Ryan surname. Examples include Ryan Lacken, Ryan Luke and Ryan Doc. A man christened Thomas Ryan might be known as Tommy Doc and his family might be referred as the Docs. While the additive is not part of a person's official name, it may be used in a postal address, on an election register or in newspaper reports. In this case, Tommy Doc might be written as Thomas Ryan (D).
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