Submitted Name Save Type Surname Usage Irish Pronounced Pron. SHAN-A-HAN [key] Other Forms FormsO'Shanahan, Shahan, Shannon, O'Shannon, Gilshenan Edit Status Status [history·contributorshide contributors] Added 12/25/2013 by anonymous Edited 2/13/2020 by Mike C Meaning & History Anglicised form of Ó SEANACHAIN.