Ó Cuain
Ó CUAIN—I—O Cuayn, O Quane, Quan, Quann, Quane, Quaine, (Coyne, Quaid); 'descendant of Cuan' (probably a 'pet' form of donnchuan, lord of harbours; hardly for cúán, diminutive of cú, a hound); the name of a branch of the Ui Fiachrach, anciently seated at Dun Ui Chobhthaigh, now anglicised Doonycoy, in the parish of Templeboy, Co. Sligo. At the end of the 16th century it was very scattered, but found chiefly in Cork and Limerick, in the latter of which counties it is now anglicised Quaine and Quaid.
Alphabetical Index to Irish Surnames