Heffernan

Heffernan is an Irish surname derived from the Gaelic ''Ó hIfearnáin'', which comes from the byname ''Ifearnán'' literally meaning 'little demon' or more metaphorically 'daredevil'. Heffernan gives rise to alternatives such as Heffernon and Hefferan. The name sometimes contains the O' prefix. According to historian C. Thomas Cairney, the O'Heffermans were the chiefly family of the Uaithni who were a tribe of the Erainn who were the second wave of Celts to settle in Ireland between about 500 and 100 BC. Provided by Wikipedia