Ó hOisín
Ó hOISÍN—I—O Hussine, O Hushin, Hussian, Hessian, Hession, Hishon; 'descendant of Oisín' (diminutive of os, a deer); an old surname in Connacht, where it is still common. Two members of this family filled the see of Tuam in the 11th and 12th centuries. Ó hOisín seems to have been also an alias in Munster for Ó hOiseáin, which see.
Alphabetical Index to Irish Surnames