Sharp
Sharp—This name is the anglicised form of Gearan (O'Géaráin) in the County of Donegal and other parts of the North West. Sharp is found in Perthshire where it is the anglicised form of a Highland sept name, the McIlherons of Bute.
Alphabetical Index of Anglicised Surnames in Ireland
See also Woulfe’s Irish Names and Surnames
… and O'Hart's Irish Pedigrees