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

StepLanguageWordMeaning
1IrishÓ Tiarnaigh—
2Irishtiarnalord
3Old Irishtigerna—
4Old Irishtigernaelord
5Old Irishtigern—
6Proto-Celtictigernoslord, ruler
7Proto-Celtic-īnosOf or pertaining to; -ine
8Proto-Indo-European-iHnosCreates adjectives of materials
9Proto-Indo-European-no-adjectival suffix
Every word from Proto-Indo-European -no- →Every word from Proto-Celtic -īnos →Every word from Proto-Celtic tigernos →