Adair
Adair—This name is the anglicised form of one of the "O" septs of Galloway, in Gaelic O Dáire, and is confused sometimes in Ulster, especially in Co. Monaghan, with the ancient Fermanagh sept of O Dubhdarach.
Alphabetical Index of Anglicised Surnames in Ireland
See also Woulfe’s Irish Names and Surnames
… and O'Hart's Irish Pedigrees