Mac An Gheairr, Mac An Ghirr
Mac an GHEAIRR, Mac an GHIRR—VII—M'Iyear, M'Eghir, M'Gayer, MacGarr, MacGirr, MacGerr, Gayer, and by translation, Short; 'son of the short, or low-sized, man' (Irish 'gearr' and 'giorr'). Mac an Gheairr, which may be regarded as the Connacht form of this surname, was formerly common in Sligo and Leitrim, and is now well known in Mayo. Mac an Ghirr is the Ulster form, and was common in Armagh and Tyrone. The family is supposed to be of Scottish origin, but is, more probably, an offshoot of some native family. Both variants were in use in Dublin and Wicklow.
Alphabetical Index to Irish Surnames