Ó Cuimín
Ó CUIMÍN—I—O Cumyn, Cumin, Cummin, Cummins, Cummings, &c.; 'descendant of Cuimín' (diminutive of cam, bent, crooked); the name of several distinct families in different parts of Ireland. It is a variant of Ó Comáin (which see) for which, in many instances, it has been substituted. The Sligo family of the name is a branch of the Ui Fiachrach.
Alphabetical Index to Irish Surnames