Piaras
PIARAS—VIII—Pierce, Pierse, Pearse, &c.; 'son of Piers' (an Anglo-Norman form of Petrus, Latin for Peter, very common among the early Anglo-Norman settlers in Ireland). There are, no doubt, several distinct families so called in different parts of the country. The Pierses of Kerry are stated to be a branch of the Fitzmaurices of Lixnaw.
Alphabetical Index to Irish Surnames