Tiernan Family History
Tiernan Name Meaning
Irish (Roscommon and Leitrim): shortened Anglicized form of Gaelic Ó Tíghearnáin ‘descendant of Tíghearnán’ a diminutive of Tighearna a byname meaning ‘lord master’. Compare Tierney McKiernan .
Source: Dictionary of American Family Names 2nd edition, 2022