Family History and Genealogy Resources by Surname
Kiernan Surname Origin
Carnan, Gaelic, a heap; figuratively, a strong man, a thick-set, stout man. Cearnan, local, a square, a quadrangle.
Source: An Etymological Dictionary of Family and Christian Names With an Essay on their Derivation and Import; Arthur, William, M.A.; New York, NY: Sheldon, Blake, Bleeker & CO., 1857.
Kiernan Surname Meaning and Family Facts
There is more to Kiernan family history than the origin of your surname:
A Kiernan Family History Thought:
Whenever there's a will, you'll see an heir loom.