The story
- Irish · borrowed fromÓ Fionnagáin“descendant of <i class="Latn mention" lang="ga">Fionnagán</i>”
- English todayFinnegan
Borrowed from Irish Ó Fionnagáin (“descendant of Fionnagán”). Fionnagán is a given name that descends from Old Irish Finnacán, which is typically anglicised as Finnegan itself.
Etymology from Wiktionary, CC BY-SA 4.0.