Where does “Tierney” come from?

Tierney is an English surname derived from Irish Ó Tiarnaigh, based on Irish tiarna and Old Irish tigerna.

Ancestry of “Tierney”, step by step

Step	Language	Word	Meaning
1	Irish	Ó Tiarnaigh	—
2	Irish	tiarna	lord
3	Old Irish	tigerna	—
4	Old Irish	tigernae	lord
5	Old Irish	tigern	—
6	Proto-Celtic	tigernos	lord, ruler
7	Proto-Celtic	-īnos	Of or pertaining to; -ine
8	Proto-Indo-European	-iHnos	Creates adjectives of materials
9	Proto-Indo-European	-no-	adjectival suffix

Tierney — Etymology, Origin & Word History | Etymology Explorer